衣康酸发酵研究进展

衣康酸作为一种平台化合物,可被各行业广泛用于多种高附加值产品的生产,其更是具有替代传统石油基原料的潜力,在工业生产中有着重要地位与应用前景.目前,衣康酸主要由土曲霉深层好氧发酵生产,碳源、氮源、磷酸盐、金属离子、溶解氧、pH、温度等条件对其产量影响显著.在衣康酸生产中,原料成本高是阻碍其市场进一步扩大与发展的重要因素....     

衣康酸发酵生产后提取研究

由铅盐沉淀、硫酸酸解和碳酸氢铵再生这几个步骤组成的新工艺流程,能有效地从发酵液或结晶母液中提取衣康酸。与原来的铅盐沉淀工艺相比,新工艺有流程简单、投资小、操作费用低、辅料便宜易得、副产品价值高等优点。该工艺配合衣康酸的浓缩结晶法使用,可大幅度提高总衣康酸提取得率有利于降低生产成本。     

衣康酸高产菌株的选育及发酵工艺研究

用多种诱变法对衣康酸产生菌原始菌株进行诱变,得到高产菌株16株,采用“正交试验-中心试验-正交试验”的策略优化培养基,对影响衣康酸生产的原料、水质等进行了研究。所得高产菌株生产适应性强,产酸水平为65g/100ml,残还原糖小于01g/100ml,摇床发酵周期小于96h,500L发酵罐发酵周期小于70h。     

定向选育衣康酸高产菌株的研究

以衣康酸生产菌土曲霉Ａ９００２为出发菌株,经紫外线及亚硝基胍复合诱变后再行定向选育,即在以衣康酸为唯一碳源的培养基中富集不能同化衣康酸的菌种,将将它们涂布在含乌头酸酶抑制剂（单氟醋酸）的高糖、高衣康酸平板培养基上,最后从中而筛选出一支衣康酸氧化酶弱,乌头酸酶活强,并耐自身代谢产物的高产突变株Ａ９００３。此菌株在摇瓶培养７２ｈ后,产酸为９．２％,转化率为５８．１％,在１００ｍ＾３发酵罐生产性试验中,     

氧载体发酵体系的氧传递特性及提高衣康酸产酸能力的研究

测定了不同氧载体的理化参数,研究了机械搅拌罐氧载体发酵体系中的氧载体的体积分数,搅拌转速和通风量对体积氧传递系数的影响,并推导出传质系数的关联式。实验表明,加入氧载体后,可提高发酵体系的ＫＬａ值３０－２００％,衣原酸发酵中加入氧载体正十二烷,可提高产酸１４％以上。     

离子束注入对衣康酸生产菌种的改良

用10keV、剂量5.2×10~(14)～5.2×10~(15)ions/cm~2的氮离子注入衣康酸生产菌株土曲霉A9003,在2％LiCl抗性平板筛选到一株能在39℃发酵的衣康酸高产菌株。该菌株在30L发酵罐发酵产酸7.5％,转化率60.1％,发酵周期50h。     

衣康酸生产菌种的定向选育和产酸条件的研究

通过紫外线—高温复合诱变处理衣康酸生产菌株土曲霉构Aspergillus terreus As3.2811,用以琥珀酸为唯一碳源的选择性乎板定向筛选高产菌株,获得产酸率较其亲株提高了5倍以上的突变株。用正交试验的方法对突变株的适宜产酸条件进行了研究,通过分批补糖发酵可提高其产酸率高达39．92％。     

酶制剂工业概况及其应用进展

概述了国内外酶制剂工业的生产和市场的情况,并介绍了酶制剂应用的进展,对于我国酶制剂工业的发展也作了展望。     

微生物发酵生产有机酸研究进展

发酵工程是生物技术的重要组成部分,微生物发酵生产是其研究成果转化为现实生产力并形成产业取得经济效益的一个重要环节。大多数有机酸均可通过微生物发酵进行生产,有此有机酸已进入工业化生产,其产品进入商业化,为食品、医药、化工以及农业等各个行业服务。这里仅介绍5种重要有机酸微生物发酵生产研究开发所取得的成果。一、乳酸L-乳酸已广泛应用于食品、医药、农业和化工等方面,它是食品工业的重要酸味剂、防腐剂;聚L-乳酸可用于制造生物塑料。美国、日本及欧洲一些国家的乳酸工业有较大发展。乳酸制成饮料,用于降低血压,这主要…     

Synthesis of itaconic acid from agricultural waste using novel Aspergillus niveus

Abstract

Filamentous fungi from the genus Aspergillus are of high importance for the production of organic acids. Itaconic acid (IA) is considered as an important component for the production of synthetic fibers, resin, plastics, rubber, paints, coatings, adhesives, thickeners and binders. Aspergillus niveus MG183809 was isolated from the soil sample (wastewater unit) which was collected from Avadi, Chennai, India. In the present study, itaconic acid was successfully produced by isolated A. niveus by submerged batch fermentation. In the fermentation process, various low-cost substrates like corn starch, wheat flour and sweet potato were used for itaconic acid production. Further, the factor influencing parameters such as substrate concentration and incubation period were optimized. Maximum yield of itaconic acid (15.65?±?1.75?g/L) was achieved by using A. niveus from corn starch at a concentration of 120?g/L after 168?hr (pH 3.0). And also extraction of itaconic acid from the fermentation was performed with 91.96?±?1.57 degree of extraction.     

Production of itaconic acid from pentose sugars by Aspergillus terreus

Itaconic acid (IA), an unsaturated 5‐carbon dicarboxylic acid, is a building block platform chemical that is currently produced industrially from glucose by fermentation with Aspergillus terreus. However, lignocellulosic biomass has potential to serve as low‐cost source of sugars for production of IA. Research needs to be performed to find a suitable A. terreus strain that can use lignocellulose‐derived pentose sugars and produce IA. One hundred A. terreus strains were evaluated for the first time for production of IA from xylose and arabinose. Twenty strains showed good production of IA from the sugars. Among these, six strains (NRRL strains 1960, 1961, 1962, 1972, 66125, and DSM 23081) were selected for further study. One of these strains NRRL 1961 produced 49.8 ± 0.3, 38.9 ± 0.8, 34.8 ± 0.9, and 33.2 ± 2.4 g IA from 80 g glucose, xylose, arabinose and their mixture (1:1:1), respectively, per L at initial pH 3.1 and 33°C. This is the first report on the production of IA from arabinose and mixed sugar of glucose, xylose, and arabinose by A. terreus. The results presented in the article will be very useful in developing a process technology for production of IA from lignocellulosic feedstocks. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1059–1067, 2017     

真菌发酵生产γ-亚麻酸的研究进展

综述了国内外微生物发酵生产γ-亚麻酸（GLA）的研究进展,对菌株诱变选育研究和基因工程菌株的构建情况进行了阐述,并展望了其发展前景。     

Integrated process development of a reactive extraction concept for itaconic acid and application to a real fermentation broth

Itaconic acid (IA) has a high potential to be used as a bio‐based platform chemical and its biocatalytic production via fermentation has significantly improved within the last decade. Additionally downstream processing using reactive extraction (RE) was described, potentially enabling a more efficient sustainable bioprocess producing IA. The bottleneck to overcome is the connection of up‐ and downstream processing, caused by lack of biocompatibility of the RE systems and direct application to fermentation broth. Within this study, a biocompatible RE system for IA is defined (pH dependency, extraction mechanism) and used for direct application to a fermentation broth. By optimizing the biocatalyst, the production medium, and the extraction system in an integrated approach, it was possible to define critical parameters that enabled a tuning of the overall bioprocess. With an extraction yield of Y_IA = 0.80 ± 0.03, IA could be produced as sole carboxylic acid ( = 0.490 mol/kg^aq) using a RE system consisting of ethyl oleate as organic solvent and tri‐n‐octylamine as extractant ( = 0.6 mol/kg^org). This work is a proof of concept and demonstrates that by joint consideration of up‐ and downstream processing, optimized bioprocesses can be developed.     

Emulsion liquid membrane extraction of lactic acid from aqueous solutions and fermentation broth

Studies on the batch extraction of lactic acid using an emulsion liquid membrane system are reported. The membrane phase consists of the tertiary amine carrier Alamine 336 and the surfactant Span 80 dissolved in n-heptane/paraffin and aqueous solutions of sodium carbonate in the internal phase. The effects of internal phase reagent, extraction temperature, and initial external phase pH on the extraction efficiency and the emulsion swelling are examined. A statistical factorial experiment on extraction from clarified lactic acid fermentation broth was carried out to obtain knowledge of the performance of the extraction system from a broth. The extraction efficiency from the fermentation broth is found to be lower as compared to aqueous solutions of pure lactic acid. The effect of pH and the presence of other ionic species on selectivity are discussed. (c) 1993 John Wiley & Sons, Inc.