NL2030233B1

NL2030233B1 - Adhesive from wet bacterial biomass

Info

Publication number: NL2030233B1
Application number: NL2030233A
Authority: NL
Inventors: Tamis Jelmer; James Picken Stephen
Original assignee: Paques Biomaterials Holding B V; Univ Delft Tech
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2023-06-29
Also published as: WO2023121441A1

Abstract

The present invention is in the ﬁeld of a water—based adhesive, in particular an adhesive for adhering cellulose or cellulose ﬁbres comprising materials and the like, such as paper, 5 cardboard, a method for applying the water—based adhesive, typically by applying heat during a certain time, and a product obtained by said method.

Description

P100733NL00

Adhesive from wet bacterial biomass

FIELD OF THE INVENTION

The present invention is in the field of a water-based adhesive, in particular an adhesive for adhering cellulose or cellulose fibres comprising materials and the like, such as paper, cardboard, a method for applying the water-based adhesive, typically by applying heat during a certain time, and a product obtained by said method.

BACKGROUND OF THE INVENTION

Adhesives are typically in the form of one-component (1C) and two-component (2C) adhesives/sealants. It is noted that the difference between these two is rather fundamental. A 1C system can react on its own given an auxiliary trigger or reactant. This trigger or reactant is usually oxygen or water from the air. Without (enough) of this trigger no reaction occurs and the product will not cure from its plastic state into an elastic one. This may happen for ex- ample when two plates, impenetrable for oxygen or moisture are glued full sur-face to an- other. There may be cure at the edges but there it stops. In a 2C system all necessary reactants are contained. not additional trigger or reactant is needed. Therefore both parts will also have to be packed separately and typically mixed intensely before application. Both parts must be stable between production and use. When not properly mixed this will typically lead to incon- sistencies in the cured material. Once mixed the curing reaction may start immediately, and therefore the material will have to be applied as soon as possible to prevent a too far cured product which will lead to difficulties in application and adhesion. A well-known system is an epoxy—adhesive where the epoxy is in one part and a curative amine is in the other part. Many other systems are known but all are based on this basic principle: once mixed, all necessary ingredients are there, nothing needs to get in or out. If a 2C product is used as an adhesive be- tween the plates of the example all material, not just the edges but also the middle, will fully cure. Therefore for large surfaces (and other places where one cannot rely on the external trig- ger) 2C systems are preferred. From above it may be clear that the demands and challenges presented in a 1C product are quite different from a 2C product. Intermixing of components of a 1C and 2C product will typically not be considered by the skilled person; the two products may in fact be considered mutually incompatible.

General properties of adhesives are open time (working time to make a bond, where the surface still retains sufficient tack, which can range from seconds for fast-setting adhesives to infinity for pressure-sensitive adhesives), set time (time to form a bond of acceptable strength), dry time, (initial) tack ((initial)degree of surface stickiness of the adhesive), applica- bility and adhesion to a diverse range of substrate surfaces, contactibility, flexibility of an ad- hesive film, temperature stability, storage stability, viscosity, and surface energy (influences wetting of different kind of surfaces).

Adhesives often consist of one base material with various additives. For a two-compo- nent adhesive a first and second component, each component optionally comprising more than one constituent, are mixed before applying, such as by a spray-gun, a sealant-gun typically equipped with a means of mixing both components, and a static mixer. The first and second component can typically not be stored in a mixed form.

Some of the possible base materials, each having advantages and disadvantages, are reactive poly-urethanes, silicones, poly-sulphides, silane-terminated polymers, and various other co- polymers.

Many of the prior art adhesives need to be bonded directly, typically within a few sec- onds, as the open time is relatively short. Thereafter one needs to wait until the adhesive has reacted and has obtained sufficient strength. That characteristic makes such an adhesive not suited for larger surfaces, or not very well accessible surfaces. Others may have a long open time and do not need to be bonded immediately; these consequently will suffer from an in- creased curing time thus also increasing the complete construction time of a to be bonded product.

It is often also important to have a high initial strength. For many prior art adhesive ini- tial strength is not sufficient. One has to wait until the bond is sufficiently strong. Adhesives are preferably also temperature stable. A fibre-reinforced composite (FRC) is a building mate- rial that consists of three components, namely fibres (for strength and stiffness) as a discontin- uous or dispersed phase, a matrix (binder) as a continuous phase, and the fine interphase re- gion, also known as the interface. For fibres use can be made of natural fibres, synthetics fi- bres, or a combination thereof. Examples thereof are flax, hemp, rice husk, rice hull, rice shell, cellulosic (waste streams), and plastic as ingredients. Fibres may need to be refined, blended, and compounded, such as in case of natural fibres from cellulosic waste streams. A high-strength fibre composite material in a polymer matrix can be formed thereby. The desig- nated waste or base raw materials used in this instance are those of waste thermoplastics and various categories of cellulosic waste including straw, rice husk and saw dust.

It is known that microorganisms are capable of producing biochemical compounds, such as lactic acid. Thereto typically a microbial culture is used. Therein microbial organisms reproduce in predetermined culture medium under controlled laboratory conditions. It is often essential to isolate a pure culture of microorganisms. A pure (or axenic) culture is a popula- tion of cells or multicellular organisms growing in the absence of other species or types. Re- markably also non-pure cultures are capable of producing chemical substances. Bacteria are capable of producing a wide variety of chemical substances, such as lactic acid, but also me- thane, and are therefore used in food industry, in waste treatment, and so on.

With the term “microbial process” here a microbiological conversion is meant.

Recently it has been found that biobased polymeric substances, such as extracellular polymeric substances (EPS), in particular polysaccharide comprising materials, obtainable from granular sludge can be produced in large quantities. These substances relate to biobased carboxylic acid-like chemicals, which may be present in an ionic form (e.g. cationic or ani- onic). Examples of such production methods can be found in WO2015/057067 Al, and

WO2015/050449 Al, whereas examples of extraction methods for obtaining said biobased polymers can be found in Dutch Patent application NL2016441 and in WO2015/190927 Al.

Specific examples of obtaining these substances, such as aerobic granular sludge and anam- mox granular sludge, and the processes used for obtaining them are known from Water Re- search, 2007, dot: 10.1016/j.waters.2007.03.044 (anammox granular sludge) and Water Sci- ence and Technology, 2007, 55(8-9), 75-81 (aerobic granular sludge). Further, Li et al. in “Characterization of alginate-like exopolysaccharides isolated from aerobic granular sludge in pilot plant”, Water Research, Elsevier, Amsterdam, NL, Vol. 44, No. 11 (June 1 2010), pp. 3355-3364) recites specific alginate-like EPS in relatively raw form. Though initially the term “alginate-like”, or “alginate-like EPS” (ALE) was used, the biobased polymeric substances are found to be more complex in terms of chemical building blocks present therein. Therefore the term EPS is preferred. Details of the biopolymers can also be found in these documents, as well as in Dutch Patent applications NL2011609, NL2011542, NL2011852, NL2017470, and

NL2012089. Also reference can be made to the Nereda® process. These documents, and there contents, such as characteristics (e.g. molecular weights, dynamic viscosity, shear rate, tensile strength, and flexural strength) of the biobased polymers, are incorporated by reference.

In general it has been found difficult to further process products of biological origin, or make use thereof, such as (these) microbial products, in particular biopolymers such as EPS, either in pure form as obtained from a reactor, or purified or extracted as indicated above.

The present invention relates to a water-based adhesive, and further aspects thereof, which overcomes one or more of the above disadvantages, without jeopardizing func- tionality and advantages.

SUMMARY OF THE INVENTION

The present invention relates in a first aspect to a water-based adhesive from wet microorganism biomass comprising concentrated wet biomass produced by and/or ob- tained from microorganisms, in particular bacteria, and comprising said microorgan- isms as microbial cells or parts thereof, in particular untreated biomass, such as a sus- pension of concentrated wet biomass, and a remainder substantially being water, In par- ticular >50 wt.% water, and < 99 wt.%, in particular < 95 wt.%, wherein a percentage weight is based on a total weight of the adhesive. The present biomass is produced by and/or obtained from microorganisms; such biomass is therefore in terms of character- istics very different from e.g. plant biomass, or likewise animal biomass. The present adhesive is inherently fully biodegradable and relatively cheap. It is clearly non-toxic, requires no solvents other than water, such as no organic solvents, it can be waste- based, so it may be considered fully circular. It is noted that typically such an adhesive, and in particular the biomass, is at least partly, and typically mostly of a hydrophilic nature. The biomass is typically obtained from a reactor or the like. Therein microor- ganisms are typically grown in the order of 100 ml solution/gram biomass, so about 1 wt.% biomass. Higher wight percentages of up to some 10 wt.% are sometimes feasible.

It came as a surprise that the wet biomass could be used as such as an adhesive.

As mentioned, the present adhesive is considered to be fully circular and “green”. The biomass can be used as such, possibly in concentrated form, but needs no further chem- ical or physical treatment to be used, nor need it to be extracted. So in can be used in un-treated form. In addition, the biomass itself forms the major fraction of the adhesive, atleast in terms of active compounds. No further components need to be added. The present biomass can therefore not be considered as an additional component (to other main components, the other main components providing the adhesive properties) or the like in the adhesive. This is considered rather exceptional.

In a second aspect the present invention relates to a method of applying a water-based adhesive according to the invention, comprising providing a first material and a second mate- rial, applying the adhesive to at least one surface, such as the surface of the first material or the sur-face of the second material, adhering the first material and second material, and drying the adhesive, such as by heating the adhesive. By heating the adhesive the adhesive is dried, at least mainly dried. In a further aspect the present invention relates to a product obtainable from the method of the present invention, such as adhered paper. adhered cardboard, adhered textile, a chemical filter, and a fibre-reinforcement composite.

Thereby the present invention provides a solution to one or more of the above men- tioned problems. Advantages of the present invention are detailed throughout the description.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates in a first aspect to a water-based adhesive.

In an exemplary embodiment of the present water-based adhesive the adhesive has a reduced in water content, such as by centrifugation or filter-pressing, such as < 90 wt.%., in particular < 85 wt.%, more in particular < 80 wt.%, and/or > 40 wt.%, such as > 50 wt.%, that is, the water-based adhesive is concentrated in terms of mass/volume. It is noted that the water content can be reduced, at least to some extent, though this is not directly required for the adhesive properties itself. Reduction of water content is some- what limited from a practical, and hence financial, point of view; the water content may be considered to be rather high, even after the reduction thereof.

In an exemplary embodiment of the present water-based adhesive the concentrated wet biomass is finely divided in the adhesive, such as, if required, by thorough mixing and/or milling, in particular by using a high rotation speed mixer of > 1000 rpm, such as > 10,000 rpm, such as in particles of size < Imm, in particular < 500 um. In particu- lar when the biomass is present as granules or the like a more finely divided adhesive could be preferred. Mixing and/or milling are suitable means of finely dividing.

In an exemplary embodiment of the present water-based adhesive the bacteria are selected from bacteria belonging to Proteobacteria, such as Gammaproteobacteria, such as of the order Pseudomonadaceae, such as Pseudomonas, Alphaproteobacteria, such as of the order of Rhodospirillales, such as Acetobacter bacteria (aerobic granular sludge)

or, from bacteria belonging to Planctomycetes, such as Planctomycetia, such as the or- der Planctomycetales (anammox granular sludge), such as Brocadia anammoxidans,

Kuenenia stuttgartiensis or Brocadia fulgida; or from Betaproteobacteria, such as Can- didatis Accumulibacter phosphatis, or, from eukaryotic organisms, typically monocel- 5 lular organisms, such as algae, such as brown algae. It is rather surprising that these mi- croorganisms, typically monocellular organisms, produce a biomass, or comprise a bio- mass, that can be used as such for the purpose of adhering materials.

In an exemplary embodiment of the present water-based adhesive the wet biomass comprises > 10° different microorganism species, in particular > 10% different microor- ganism species, more in particular > 10° different microorganism species. Albeit the present biomass and/or microorganisms are typically obtained from a reactor or the like, the reactor intended for a certain purpose, e.g., the production of a biological com- pound, such as lactic acid, or methane, or the cleaning of waste water, the present bio- mass and/or microorganisms comprise a multitude of different microorganism species.

So, albeit reactor conditions are preferred for certain microorganisms, still a multitude of species is and can be present, and said multitude of species is typically found in the present adhesive, as such, or as parts thereof.

In an exemplary embodiment of the present water-based adhesive the wet biomass comprises 0.001-30 wt.% glycoproteins, which are typically oligosaccharide chains, also referred to as glycans, which are covalently attached to amino acid side-chains, in particular 0.1-10 wt.%, more in particular 1-5 wt.%, based on dry biomass. The terms glycan and polysaccharide refer to compounds consisting of a large number of mono- saccharides linked glycosidically. The term glycan may also be used to refer to the car- bohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteo- glycan, even if the carbohydrate is only an oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan (or, to be more specific, a glucan) composed of B-1,4-linked D-glucose, and chitin is a glycan composed of B-1,4-linked N-acetyl-D-glucosamine. Glycans can be homo- or heteropolymers of monosaccharide residues, and can be linear or branched.

In an exemplary embodiment of the present water-based adhesive the wet biomass comprises 0.00-15 wt.% bio-polyester, in particular 0.1-10 wt.% bio-polyester, more in particular 0.3-3 wt.% bio-polyester, such as 0.4-1 wt.% bio-polyester, based on dry bio- mass. Said bio-polyester may be present in the reactor or the like, in relative small amounts, in particular when the reactor is intended to produce such bio-polyesters, or parts thereof, such as in the case of lactic acid production.

In an exemplary embodiment of the present water-based adhesive the bio-polyes- ter is selected from polyhydroxy alkanoates (PHA), preferably wherein the PHA is formed from C2-C7 carboxylic acids, such as Poly(3-hydroxybutyrate-co-3-hy-

droxyvalerate) (PHBV), polylactic acid (PLA), and poly hydroxy butyrate (PHB), hy- brid polymers thereof, and block- or co-polymers thereof, and combinations thereof.

In an exemplary embodiment of the present water-based adhesive the bio-polyes- ter is an intracellular produced bio-polyester.

In an exemplary embodiment of the present water-based adhesive the adhesive is obtained directly from bacterial sludge (such as in a Nereda reactor, or from activated sludge).

In an exemplary embodiment of the present water-based adhesive the biomass is obtained from granular sludge by sieving, such as using a sieve of < 4 mm.

In an exemplary embodiment the present water-based adhesive comprises 0.1-25 wt.% biomass, in particular 1-20 wt.% biomass, more in particular 5-15 wt.% biomass, and 0-23 wt.% bio-polyester, in particular 0.01-12.5 wt.% bio-polyester, more in particular 5-10 wt.% bio-polyester, and 0.0001-15 wt.% glycoproteins, in particular 0.01-10 wt.% glycoproteins, more in par- ticular 0.1-8 wt.% glycoproteins, and 0-15 wt.% lipids, in particular 0.01-10 wt.%, such as 0.02-2 wt.%, and 0-20 wt.% exopolysaccharides, in particular 0.5-10 wt.%, such as 1-5 wt.%, and 0-15 wt.% proteins, in particular 0.1-10 wt.%, such as 1-5 wt.%, aremainder being water.

In an exemplary embodiment of the present water-based adhesive the water-based adhesive comprises a high biomass of 40-60 wt.% bacterial cells thereof, based on a dry mass.

In an exemplary embodiment of the present water-based adhesive the water-based adhesive is a directly applicable adhesive with a low biomass of 5-25 wt.% bacterial cells, based on a dry mass.

In an exemplary embodiment of the present water-based adhesive the concentrated wet bio-mass is produced in a reactor and directly provided therefrom.

In an exemplary embodiment of the present water-based adhesive the adhesive has atackiness/peel strength of > 30 J/m?, [ISO 11339:2010], in particular > 100 J/m?.

Such a peel strength is rather high, and sufficient for many applications.

In an exemplary embodiment of the present water-based adhesive the adhesive comprises 10-10 wt.% microbial DNA, in particular 10-5 wt.%, more in particular 101-3 wt.%, that is, traces of the microbial DNA are typically present in the present adhesive.

In an exemplary embodiment of the present water-based adhesive the adhesive comprises >5 wt.% microbial cells or parts thereof, in particular > 10 wt.% microbial cells.

In an exemplary embodiment of the present water-based adhesive the bio-polyes- ter, when present, in the adhesive has a melting point or melting range of 80-220 °C, in particular 90-130 °C).

In an exemplary embodiment of the present water-based adhesive the bio-polyes- ter of the adhesive has a glass transition temperature of < 50 °C, preferably < 40 °C, such as < 20 °C, in particular < 0 °C, (measured using differential scanning calorime- try with Mettler Toledo TGA2 according to ISO 11357-1:2016).

In an exemplary embodiment of the present water-based adhesive the biomass comprises biopolymer which is anionic or cationic.

In an exemplary embodiment of the present water-based adhesive the biopolymer is a non-linear biopolymer.

In an exemplary embodiment of the present water-based adhesive the biopolymer has an average molecular weight of >5kDa (size exclusion chromatography), preferably > 10 kDa, more preferably >20 kDa, such as > 100 kDa.

In an exemplary embodiment of the present water-based adhesive the biopolymer has an average molecular weight of <1500 kDa (size exclusion chromatography, prefer- ably < 1000 kDa, more preferably <500 kDa.

In an exemplary embodiment of the present water-based adhesive the biopolymer has a chemical multifunctionality.

The above are some characteristics of exemplary biopolymers that can be present in the present biomass.

In an exemplary embodiment of the present method heat is applied during 0.01-5 minutes, in particular during 0.1-2 minutes, such as 0.5-1 minute.

In an exemplary embodiment of the present method the temperature of the adhe- sive is increased to 25-300 °C, in particular to 50-200 °C, such as by using an iron.

In an exemplary embodiment of the present method the first material and a second material are each individually selected from natural or processed cellulose or cellulose fibres comprising materials, such as paper, and cardboard, and from hemicellulose com- prising materials, and from lignin com-prising materials.

In an exemplary embodiment of the present product is adhered paper, adhered cardboard, adhered textile, a chemical filter, and a fibre-reinforcement composite.

The invention is further detailed by the accompanying examples, which are ex- emplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.

EXAMPLES/EXPERIMENTS

The invention although described in detailed explanatory context may be best un- derstood in conjunction with the accompanying examples.

Sludge was directly obtained from an aerobic bioreactor fed with leachate from organic waste. The sludge was then concentrated, using a centrifuge at 3000 g during 2 minutes, to a dry solids content of 15% (w/w). The sludge as such was applied on a first piece of cardboard and a second piece of cardboard was placed on top. This “cardboard sandwich” was subse- quently heated using an iron at 150-175 °C until the lion-share of the water was evaporated, which was after about 60 seconds. After this, the two pieces of cardboard were found to stick together. The bonding between the two pieces was so strong, that it was not possible to sepa- rate the pieces without breaking them. The force applied was estimated to be > 100 N/m (100

N-m/m? or 100 J/m?). Suitable test procedures are ISO 11339: Adhesives — T-peel test for flexible-to-flexible bonded assemblies [N/cm]: ISO 16260: Paper and board — Determination of internal bond strength [J/m?}; ASTM 3165-07: Standard Test Method for Strength Proper- ties of Adhesives in Shear by Tension Loading of Single-Lap-Joint Laminated Assemblies [N/m?].

For the purpose of searching the following section is added, which may be considered embodiments of the present invention. and of which the subsequent section represents a trans- lation into Dutch. 1. A water-based adhesive from wet microorganism biomass comprising concentrated wet biomass produced by and/or obtained from microorganisms, in partic- ular bacteria, and comprising said microorganisms as microbial cells or parts thereof, in par- ticular untreated biomass, such as a suspension of concentrated wet biomass, and a remainder substantially being water, in particular >50 wt.% water, and < 99 wt.%, in particular < 95 wt.%, wherein a percentage weight is based on a total weight of the adhesive. 2. The water-based adhesive according to embodiment 1, wherein the adhesive has a reduced in water content, such as by centrifugation or filter-pressing, such as < 95 wt.%., in particular < 90 wt.%, more in particular < 80 wt.%, and/or > 40 wt.%, such as > 50 wt.%. 3. The water-based adhesive according to any of embodiments 1-2, wherein the concentrated wet biomass is finely divided in the adhesive, such as by thorough mixing and/or milling, in particular by using a high rotation speed mixer of > 1000 rpm, such as > 10,000 rpm, such as in particles of size < 1mm, in particular < 500 um. 4. The water-based adhesive according to any of embodiments 1-3, wherein the bacteria are selected from bacteria belonging to Proteobacteria, such as Gammaproteobacteria, such as of the order Pseudomonadaceae, such as Pseudomonas, Alphaproteobacteria, such as of the order of Rhodospirillales, such as Acetobacter bacteria (aerobic granular sludge) or, from bacteria belonging to Planctomycetes, such as Planctomycetia, such as the order

Planctomycetales (anammox granular sludge), such as Brocadia anammoxidans,

Kuenenia stuttgartiensis or Brocadia fulgida; or from Betaproteobacteria, such as Can- didatis Accumulibacter phosphatis, or, from eukaryotic organisms, typically monocellular organisms, such as algae, such as brown algae, and/or wherein the wet biomass comprises > 10° different microorganism species, in particular > 10% different microorganism species, more in particular > 10° different microorganism species. 5. The water-based adhesive according to any of embodiments 1-4, wherein the wet biomass comprises 0.001-30 wt.% glycoproteins, in particular 0.1-10 wt.%, more in particular 1-5 wt.%, based on dry biomass, and/or wherein the wet biomass comprises 0.00-15 wt.% bio-polyester, in particular 0.1-10 wt.% bio-polyester, more in particular 0.3-3 wt.% bio-polyester, such as 0.4-1 wt.% bio-polyester, based on dry biomass. 6. The water-based adhesive according to embodiment 5, wherein the bio-polyester is selected from polyhydroxy alkanoates (PHA), preferably wherein the PHA is formed from C2-C7 car- boxylic acids, such as Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polylactic acid (PLA), and poly hydroxy butyrate (PHB), hybrid polymers thereof, and block- or co-polymers thereof, and combinations thereof, and/or wherein the bio-polyester is an intracellular produced bio-polyester.

7. The water-based adhesive according to any of embodiments 1-6, wherein the adhesive is obtained directly from bacterial sludge, and/or wherein the biomass is obtained from granular sludge by sieving, such as using a sieve of <4 mm.

8. The water-based adhesive according to any of embodiments 1-7, comprising

0.1-25 wt.% biomass, in particular 1-20 wt.% biomass, more in particular 5-15 wt.% biomass, and 0-23 wt.% bio-polyester, in particular 0.01-12.5 wt.% bio-polyester, more in particular 5-10 wt.% bio-polyester, and 0.0001-15 wt.% glycoproteins, in particular 0.01-105 wt.% glycoproteins, more in particular

0.1-8 wt.% glycoproteins, and 0-15 wt.% lipids, and 0-20 wt.% exopolysaccharides, and 0-15 wt.% proteins,

a remainder being water.

9. The water-based adhesive according to any of embodiments 1-8, wherein the water-based adhesive comprises a high biomass of 40-60 wt.% bacterial cells, based on a dry mass, or wherein the water-based adhesive is a directly applicable adhesive with a low biomass of 5-25 wt.% bacterial cells, based on a dry mass.

10. The water-based adhesive according to any of embodiments 2-9, wherein the concentrated wet biomass is produced in a reactor and directly provided therefrom, and/or wherein the adhesive has a tackiness/peel strength of > 30 J/m?, in particular > 100 J/m?.

11. The water-based adhesive according to any of embodiments 1-10, wherein the adhesive comprises 10-10 wt.% microbial DNA, and/or wherein the adhesive comprises >5 wt.% microbial cells or parts thereof, in particular > 10 wt.% microbial cells. 12. The water-based adhesive according to any of embodiments 1-11, wherein the biomass comprises biopolymer which is anionic or cationic, and/or wherein the biopolymer is a non-linear biopolymer, and/or wherein the biopolymer has an average molecular weight of >5kDa (size exclusion chroma-

tography), preferably > 10 kDa, more preferably >20 kDa, such as > 100 kDa, and/or wherein the biopolymer has an average molecular weight of <1500 kDa (size exclusion chro- matography, preferably < 1000 kDa, more preferably <500 kDa, and/or wherein the biopolymer has a chemical multifunctionality.

13. Method of applying a water-based adhesive according to any of embodiments 1-12, com- prising providing a first material and a second material, applying the adhesive to at least one surface, such as the surface of the first material or the surface of the second material,

adhering the first material and second material, and drying the adhesive, such as by heating the adhesive. 14. Method according to embodiment 13, wherein heat is applied during 0.01-5 minutes, and/or wherein the temperature of the adhesive is increased to 25-300 °C, in particular to 50-220 °C,

such as by using an iron. 15. Method according to embodiment 13 or 14, wherein the first material and a second mate- rial are each individually selected from natural or processed cellulose or cellulose fibres com- prising materials, such as paper, and cardboard, and from hemicellulose comprising materials, and from lignin comprising materials.

16. Product obtainable from the method of any of embodiments 13-15, such as adhered paper, adhered cardboard, adhered textile, a chemical filter, and a fibre-reinforcement composite.

Claims

Conclusions

I. A water based adhesive from wet biomass of microorganisms comprising concentrated wet biomass produced by and/or derived from microorganisms, especially bacteria, and comprising those microorganisms as microbial cells or parts thereof, in particular untreated biomass, such as a slurry of concentrated wet biomass, and a residue consisting mainly of water, in particular > 50% by weight of water, and < 99% by weight, in particular < 95% by weight, with a weight percentage is based on a total weight of the adhesive.

The water-based adhesive according to claim 1, wherein the adhesive has a reduced water content, such as by centrifugation or filter pressing, such as < 95 wt.%, especially < 90 wt.%, more especially < 80 wt.%. %, and/or > 40% by weight, such as > 50% by weight.

The water-based adhesive according to any one of claims 1-2, wherein the concentrated wet biomass is finely dispersed in the adhesive, such as by thorough mixing and/or grinding, in particular by using a high-speed mixer. rotational speed of > 1000 revolutions per minute, such as > 10,000 revolutions per minute, such as in particles with a size < 1 mm, especially < 500 µm.

The water-based adhesive according to any one of claims 1 to 3, wherein the bacteria are selected from bacteria belonging to the Proteobacteria, such as Gammaproteobacteria, such as the order Pseudomonadaceae, such as Pseudomonas, Alphaproteobacteria, such as the order Rhodospirillales, such as Acetobacter bacteria (aerobic granular sludge) or from bacteria belonging to the Planctomycetes, such as Planctomycetia, such as from the order Planctomycetales (anammox granular sludge), such as Brocadia anammoxidans, Kuenenia stuttgartiensis or Brocadia fulgida or from Betaproteobacteria, such as Candidatis Accumulibacter phosphatis, or from eukaryotic organisms, typically unicellular organisms, such as algae, such as brown algae, and/or where the wet biomass contains > 103 different types of micro-organisms, in particular > 10% different types of micro-organisms, more in particular > 10° different types of micro-organisms.

The water-based adhesive according to any one of claims 1-4, wherein the wet biomass comprises 0.001-30% by weight of glycoproteins, especially 0.1-10% by weight, more especially 1-5% by weight %, based on dry biomass, and/or in which the wet biomass comprises 0.00-15 wt.% bio-polyester, in particular 0.1-10 wt.% bio-polyester, more in particular 0.3- 3 wt.% bio-polyester, such as 0.4-1 wt.% bio-polyester, based on dry biomass.

The water-based adhesive according to claim 5, wherein the biopolyester is selected from polyhydroxyalkanoates (PHA), preferably wherein the PHA is formed from C2-C7 carboxylic acids, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polylactic acid

(PLA), and polyhydroxybutyrate (PHB), hybrid polymers thereof, and block or copolymers thereof, and combinations thereof, and/or wherein the biopolymer is an intracellularly produced biopolymer.

The water-based adhesive according to any one of claims 1-6, wherein the adhesive is obtained directly from bacterial sludge, and/or wherein the biomass is obtained from granular sludge by sieving, for example with a sieve of <4 mm.

The water-based adhesive according to any one of claims 1-7, comprising 0.1-25 wt% biomass, especially 0.2-20 wt% biomass, more especially 05-15 wt% biomass and 0-23 wt.% bio-polyester, in particular 0.01-12.5 wt.% bio-polyester, more in particular 5-10 wt.% bio-polyester, and 0.0001-15 wt. .% glycoproteins, especially 0.01-10 wt.% glycoproteins, more especially 0.1-8 wt.% glycoproteins, and 0-15 wt.% lipids, and 0-20 wt.% exopolysaccharides, and 0-15 wt.% protein, the balance being water.

The water-based adhesive according to any one of claims 1-8, wherein the water-based adhesive contains a high biomass of 40-60 weight percent bacterial cells, based on dry weight, or wherein the water-based adhesive is a ready-to-apply adhesive having a low biomass of 5-25 wt.% bacterial cells, based on dry weight.

The water-based adhesive according to any one of claims 2-9, wherein the concentrated wet biomass is produced in a reactor and provided directly therefrom, and/or wherein the adhesive has a tack/tack strength of > 30 J /m 2 , in particular > 100 J/m 2 .

The water-based adhesive according to any one of claims 1-10, wherein the adhesive comprises 107-10% by weight of microbial DNA, and/or when the adhesive comprises >5% by weight of microbial cells or parts thereof, in particular > 10 wt% microbial cells.

The water-based adhesive according to any one of claims 1-11, wherein the biomass is biopolymer which is anionic or cationic, and/or wherein the biopolymer is a non-linear biopolymer, and/or when the biopolymer has an average molecular weight of > 5 kDa (size extraction chromatography), preferably > 10 kDa, more preferably > 20 kDa, such as > 100 kDa, and/or wherein the biopolymer has an average molecular weight of < 1500 kDa (size exclusion chroma -tography), preferably < 1000 kDa, more preferably < 500 kDa, and/or wherein the biopolymer has a chemical multi-functionality.

A method of applying a water-based adhesive according to any one of claims 1 to 12, comprising stretching a first material and a second material, applying the adhesive to at least one surface, such as the surface of the first material or the surface of the second material, bonding the first material and the second material, and drying the adhesive, such as by heating the adhesive.

A method according to claim 13, wherein heat is applied for 0.01-5 minutes, and/or wherein the temperature of the adhesive is raised to 25-300°C, in particular to 50-220°C, for example using of an iron.

A method according to claim 13 or 14, wherein the first material and a second material are each individually selected from natural or processed cellulose or cellulosic fiber-comprising materials, such as paper, and cardboard, and from hemicellulose-comprising materials, and from lignin including materials.

A product obtainable according to the method of any one of claims 13-15, such as pasted paper, pasted cardboard, pasted textile, a chemical filter, and a fibre-reinforced composite.