CN1264970C - Compound type biological flocculating agent two-stage fermentation method - Google Patents

Abstract

The present invention relates to a compound biological flocculant two-stage fermentation method, particularly to fermentation technology of a flocculant. The present invention is realized by the following steps: a. cellulose biological materials are used as raw materials, and a physical-chemical combined method is used for pretreating the raw materials; b. culture solution is prepared; inorganic salt is added to the culture solution; after the pH value is regulated, the culture solution is sterilized for spare use; c. cellulose degrading bacteria are added to the culture solution; cellulose is converted into dextrose and cellobiose to complete the first stage of fermentation; d. flocculant generating bacteria are added to the culture solution to generate a compound biological flocculant. The present invention uses mixed fermentation technology to combine the two processes of cellulose degradation and flocculant generation by microorganisms organically to optimize the whole technological flow path; the production cost is low; efficient cellulose degrading bacteria can be used for realizing that enzyme generation and enzyme hydrolysis can be carried out in the same system, so the step of enzyme extraction can be omitted to prevent the enzyme activity from being partially lost in the extraction; the technological flow path is shortened, and the preparation cost is greatly reduced.

Description

Compound biological flocculant two-section type fermentation process

Technical field:

The present invention relates to a kind of zymotechnique of flocculation agent.

Background technology:

In cities and towns water and the Industrial Wastewater Treatment, flocculation (coagulation) process is to use one of the most general key link, and the flocculation agent of therefore developing high effect nontoxic becomes the important content in present environmental science and the engineering field.Research tendency that it should be noted that current flocculation process is to develop into the exploitation that stresses medicament now gradually by the optimization that stresses technology in the past.Biological flocculant (Bioflocculant) is that a class is by cohesion, the sedimentary special polymer meta-bolitess such as solid suspended particle, somatic cells and colloidal particle that are difficult for degraded in the made liquid of microorganisms.At present, the preparation of biological flocculant utilizes sugar or agricultural byproducts as raw materials for production more, thinking according to food fermentation and bio-pharmaceuticals prepares biological flocculant, promptly adopt single culture and expensive substratum, preparation cost is higher, both increased production cost, and aggravated the contradiction that people and animals strive grain again, the transformation efficiency and the utilization ratio of biomass energy are lower.Therefore, seeking a kind of more cheap biological flocculant raw materials for production is very important.At present, the research of cellulose-degrading bacteria both at home and abroad concentrates on the extraction and the structural analysis aspect thereof of high efficiency cellulose, produces enzyme and separates with enzymic hydrolysis and carry out; Concentrate in the screening of mould in the cellulose-degrading bacteria, very few to the research of bacterium.

Summary of the invention:

The purpose of this invention is to provide a kind of compound biological flocculant two-section type fermentation process, this method directly adopts the highly effective cellulose bacterium for degrading, enzyme is produced in realization and enzymic hydrolysis can be carried out in same system, then can save this step of enzyme extraction, avoid the part forfeiture of enzyme work in extraction, shortened process, and reduce preparation cost greatly.The present invention is achieved in that a, adopts the cellulose series biomass material is starting material, uses the method for physical-chemical coupling to carry out pre-treatment; B, preparation nutrient solution, wherein raw material accounts for 1～5% of nutrient solution mass volume ratio, to wherein adding inorganic salt, regulates pH value to 7.2～7.5 after sterilising treatment is standby with NaOH simultaneously; C, in above-mentioned nutrient solution, add cellulose-degrading bacteria, with cellulose conversion is glucose and cellobiose, control connects that bacterium amount is 2～6%, leavening temperature is that 30～50 ℃, fermentation time are that 70～80h, air demand are 60～80%, rotating speed is 300～350r/min, finishes first section fermentation; D, add bacterium for producing flocculant after first section fermentation ends, generate compound biological flocculant, control connects that the bacterium amount is 4～6%, leavening temperature is that 25～40 ℃, fermentation time are that 24～30h, air demand are 50～70%, rotating speed is 300～350r/min; Described physical-chemical coupling method is: 1. elder generation is with the raw material mechanical disintegration, 2. again with taking off the wooden chemistry agent treated, 3. using steamed quick-fried again after the processing; The composition of the inorganic salt that add in the described nutrient solution consists of: 0.5～5g/LKH ₂PO ₄, 0.1～1g/L MgSO ₄7H ₂O, 0.1g/L NaCl, 0.01～0.05g/L FeCl ₃, 1.0～5g/L NaNO ₃Described cellulose-degrading bacteria is Alcaligenes xylosoxidans or Alcaligenes faecalis; Described bacterium for producing flocculant is micrococcus sp or bacillus.The present invention utilizes the technology of mixed fermentation, with cellulose degradation and two process organic assembling of production by biological wadding, realizes the optimization of whole process flow, low production cost.This technology is started with from reducing material cost, with the natural agro-ecology matter solid waste replacement high value raw material of cheapness, thereby solves this bottleneck, is easy to realization of industrialization.Compound biological flocculant two-section type zymotechnique of the present invention is mainly in order to realize the suitability for industrialized production of efficient flocculant product.This technology has the following advantages: (1) starting material wide material sources, realize making full use of of biomass energy: the stalk fibrid element is the abundant organic resource of available regeneration of earth surface, reproduction speed is fast, and contain very high energy, have a lot of potential using values, the plain part of removing of China's stalk fibrid is used for paper pulp, wood sugar, outside the production of product such as furfural and edible mushrooms, major part does not obtain reasonable use, wherein a part of vegetable fibre is all burnt in vain, this is not only the serious waste to efficient resource, and can cause the serious environmental pollution problem, destroy human environment of depending on for existence, consider that from the STRATEGIES OF SUSTAINABLE DEVELOPMENT angle renewable resources that develops this cheapness has far-reaching social effect and economic worth; (2) the highly effective cellulose bacterium for degrading is realized synchronous saccharification: the present invention directly adopts the highly effective cellulose bacterium for degrading, enzyme is produced in realization and enzymic hydrolysis can be carried out in same system, then can save this step of enzyme extraction, avoid the part forfeiture of enzyme work in extraction, shortened process, and reduce preparation cost greatly, be easy to realize; (3) saccharification of cellulose section and the biological flocculant section of producing coupling: cellulosic degraded product is very fast in the fermentation system is utilized by flocculated bacteria, eliminated the effect of checking of the degradation product that cellulase may be subjected in synthetic, enzyme can constantly be generated, also removed simultaneously the feedback inhibition of enzymatic reaction end product to enzyme, enzyme is degraded to substrate to greatest extent, realize high conversion coefficient, the sugar that produces is " coexistence bacterium ", it is flocculated bacteria, the necessary carbon source of growing is provided, the two alternate and symbiosis have been realized, realized the organic assembling of two processes of cellulose degradation and production by biological wadding, can obtain efficient on the one hand, cheap microbial flocculant has been opened up a new way for the resource utilization of the agricultural wastes of rich cellulose such as stalk on the other hand.

Embodiment:

Embodiment one: present embodiment is achieved in that cellulose series biomass materials such as a, employing stalk are starting material, use the method for physical-chemical coupling to carry out pre-treatment, to improve the cellulosic degradation rate of follow-up fermentation stage, that is: 1. earlier with the raw material mechanical disintegration, 2. again with taking off the wooden chemistry agent treated, 3. use steamed quick-fried again after handling, further break the crystalline texture and the protective layer of cellulosic molecule, make material become fluffy; B, preparation nutrient solution, wherein raw material accounts for 1～5% of nutrient solution mass volume ratio, to wherein adding inorganic salt, to satisfy the nutritional requirement of microbial fermentation, regulates pH value to 7.2～7.5 after sterilising treatment is standby with NaOH simultaneously; C, first section fermentation unit are the saccharification of cellulose section, in above-mentioned nutrient solution, add cellulose-degrading bacteria, with cellulose conversion is glucose and the cellobiose that bacterium is easy to utilize, finish cellulosic efficiently saccharifying process, control connects that bacterium amount is 2～6%, leavening temperature is that 30～50 ℃, fermentation time are that 70～80h, air demand are 60～80%, rotating speed is 300～350r/min, finishes first section fermentation; D, second section fermentation unit are that bacterium for producing flocculant produces the wadding section, promptly utilize saccharification liquid to produce the biological flocculant section, after first section fermentation ends, add bacterium for producing flocculant, generate compound biological flocculant, control connects that the bacterium amount is 4～6%, leavening temperature is that 25～40 ℃, fermentation time are that 24～30h, air demand are 50～70%, rotating speed is 300～350r/min.Described inorganic salt are made up of following compositions: 0.5～5g/L KH ₂PO ₄, 0.1～1g/L MgSO ₄7H ₂O, 0.1g/L NaCl, 0.01～0.05g/L FeCl ₃, 1.0～5g/L NaNO ₃Described cellulose-degrading bacteria is Alcaligenes xylosoxidans Achromobacter xylosoxidans sp. or Alcaligenes faecalis Alcaligenesfaecalis sp.; Described bacterium for producing flocculant is micrococcus sp Micrococcus sp. or bacillus Bacillus sp..

Embodiment two: present embodiment is achieved in that a, adopts stalk cellulose biolobic material material is starting material, use the method for physical-chemical coupling to carry out pre-treatment, to improve the cellulosic degradation rate of follow-up fermentation stage, that is: 1. earlier with the raw material mechanical disintegration, 2. again with taking off the wooden chemistry agent treated, 3. use steamed quick-fried again after handling, further break the crystalline texture and the protective layer of cellulosic molecule, make material become fluffy; B, preparation nutrient solution, wherein raw material accounts for 1% of nutrient solution mass volume ratio, and simultaneously to wherein adding inorganic salt, to satisfy the nutritional requirement of microbial fermentation, described inorganic salt are made up of following compositions: 1g/L KH ₂PO ₄, 0.3g/L MgSO ₄7H ₂O, 0.1g/L NaCl, 0.01g/LFeCl ₃, 2.5g/L NaNO ₃, regulate pH value to 7.2～7.5 after sterilising treatment is standby with NaOH; C, first section fermentation unit are the saccharification of cellulose section, in above-mentioned nutrient solution, add Alcaligenes xylosoxidans, with cellulose conversion is glucose and the cellobiose that bacterium is easy to utilize, finish cellulosic efficiently saccharifying process, control connects that bacterium amount is 2～6%, leavening temperature is that 30 ℃, fermentation time are that 72h, air demand are 60%, rotating speed is 325r/min, finishes first section fermentation; D, second section fermentation unit are that bacterium for producing flocculant produces the wadding section, promptly utilize saccharification liquid to produce the biological flocculant section, after first section fermentation ends, add micrococcus sp, generate compound biological flocculant, control connects that the bacterium amount is 4～6%, leavening temperature is that 28 ℃, fermentation time are that 24h, air demand are 60%, rotating speed is 325r/min.

Claims (2)

1, compound biological flocculant two-section type fermentation process, it is characterized in that it is achieved in that a, adopts the cellulose series biomass material is starting material, uses the method for physics-chemical coupling to carry out pre-treatment: 1. elder generation is with the raw material mechanical disintegration, 2. again with taking off the wooden chemistry agent treated, 3. using steamed quick-fried again after the processing; B, preparation nutrient solution, wherein raw material accounts for 1～5% of nutrient solution mass volume ratio, adds inorganic salt 0.5～5g/L KH simultaneously ₂PO ₄, 0.1～1g/L MgSO ₄7H ₂O, 0.1g/L NaCl, 0.01～0.05g/L FeCl ₃, 1.0～5g/L NaNO ₃, regulate pH value to 7.2～7.5 after sterilising treatment is standby with NaOH; C, in above-mentioned nutrient solution, add Alcaligenes xylosoxidans or Alcaligenes faecalis, with cellulose conversion is glucose and cellobiose, control connects that bacterium amount is 2～6%, leavening temperature is that 30～50 ℃, fermentation time are that 70～80h, air demand are 60～80%, rotating speed is 300～350r/min, finishes first section fermentation; D, after first section fermentation ends, add micrococcus sp or bacillus, generate compound biological flocculant, control connects that the bacterium amount is 4～6%, leavening temperature is that 25～40 ℃, fermentation time are that 24～30h, air demand are 50～70%, rotating speed is 300～350r/min.

2, compound biological flocculant two-section type fermentation process according to claim 1 is characterized in that the inorganic salt that add in the nutrient solution are made up of following compositions: 1g/L KH ₂PO ₄, 0.3g/LMgSO ₄7H ₂O, 0.1g/L NaCl, 0.01g/L FeCl ₃, 2.5g/L NaNO ₃