共固定化生物催化剂的制备及其应用

固定化酶和固定化细胞业已用于工业、化学分析、环境保护等领域。近年来建立的酶与微生物细胞(或二种微生物细胞)共固定化技术,进一步扩大了固定化生物催化剂的应用范围。本文就共固定化生物催化剂的制备方法及其在食品发酵工业中的应用作一概要介绍。     

细胞固定化技术及其应用的研究进展

本文对细胞固定化的方法做了系统阐述,探讨了细胞固定化技术的研究进展及其在发酵、制药、环境等领域的广泛应用,最后展望了细胞固定化技术的应用前景。     

固定化生物催化剂的研究动向

近年来,国内外对于固定化酶、固定化细胞、固定化细胞器以及生物传感器的研究很活跃,在固定化方法上取得了较大进展,一部分固定化酶、固定化微生物细胞以及生物传感器在食品发酵工业、有机合成工业、化学分析、临床诊断以及能源开发等方面得到了应用。目前,大多数固定化酶、固定化细胞以及生物传感器还处在实验室研究阶段或中试阶段,有待改进;动物细胞、植物细胞以及细胞器的固定化研究还处于探索阶段、有待深入。     

固定化细胞技术及其应用研究进展

细胞固定技术是将具有特定生理功能的生物细胞用一定的方法进行固定,并以其作为生物催化剂加以利用的一门技术。相对于游离的单细胞,固定化细胞可简化生产工艺,降低生产成本。本文回顾了细胞固定技术在制备方法和载体材料等方面的研究进展,并总结了近几年来固定化细胞技术在新能源开发、食品加工及环境污染物处理中的应用,对其发展前景进行展望。     

推动食品生物技术及产业快速创新发展

<正>食品生物技术,是指生物技术在食品领域中的应用,包括利用传统生物技术进行食品发酵和酿造,以及利用现代生物技术,如基因工程、酶工程、细胞工程、现代发酵工程、组学技术等,进行食品及食品原料的生产、加工和改良。食品生物技术作为一项极富潜力和发展空间的高新技术,以生命科学为基础,以工程技术为手段,在食品工业的现代发展中发挥着重要的推动作用。食品生物技术是一门极具包容性和关联性的综合学科,包括分子生物学、细胞生物学、微生物学、免疫学、     

固定化米根霉生产L－乳酸的研究

开发了利用聚氨酯泡沫为载体固定化米根霉生产Ｌ－乳酸的新工艺。确定了固定化细胞发酵条件：葡萄糖浓度为５０ｇ／ｌ,载体立方体边长为４～８ｍｍ,载体量为２０ｃｍ３／７０ｍｌ培养基,固定化细胞制备培养时间为２４ｈ．利用固定化细胞发酵产酸速率是游离菌的３倍以上,对糖转化率达７７．７０％,与理论转化率相近。该固定化细胞应用在反复间歇发酵中可稳定１０批次以上。     

食品生物技术相关专利分析

随着生物技术在食品工业应用日益深入,以基因工程为先导,以发酵工程、酶工程技术为核心．包括蛋白质工程和生物分离工程在内的食品生物技术已成为提升我国食品工业技术含量、参与市场竞争的重要核心技术。本文以Derwent Innovation Index（DⅡ）数据库和Aureka数据库为基础,对上游（基因工程）、中游（发酵工程、酶工程与蛋白质工程）、下游（生物分离工程、食品安全检测）食品生物技术相关专利进行研究分析。     

一种固定化酵母细胞的复合载体——PVA-海藻酸盐凝胶

固定化细胞这一生物技术在近20年来发展迅速,已涉及食品、发酵、化工、医疗、生化等各领域.新型载体研制是发展固定化细胞技术的一个主导因素.PVA(聚乙烯醇)是近年来用于固定化细胞的一种新载体材料,但目前制备PVA凝胶的方法通常是在PVA溶液凝固后(或加入固化剂、乳化剂等让其凝固)手工切块.为了解决PVA载体的成球问题,简化制备方法,我们进行了这方面的研究.本文报道了用PVA和海藻酸钠制备的一种固定化细胞载体新配方,比较了几种常用载体及几种PVA载体的性能及用于乙醇发酵的实验结果.     

一种固定化酵母细胞的复合载体——PVA-海藻酸盐凝胶

固定化细胞这一生物技术在近20年来发展迅速,已涉及食品、发酵、化工、医疗、生化等各领域.新型载体研制是发展固定化细胞技术的一个主导因素.PVA(聚乙烯醇)是近年来用于固定化细胞的一种新载体材料,但目前制备PVA凝胶的方法通常是在PVA溶液凝固后(或加入固化剂、乳化剂等让其凝固)手工切块.为了解决PVA载体的成球问题,简化制备方法,我们进行了这方面的研究.本文报道了用PVA和海藻酸钠制备的一种固定化细胞载体新配方,比较了几种常用载体及几种PVA载体的性能及用于乙醇发酵的实验结果.     

食品生产和加工的生物工程学

食品加工工业是应用生物工程技术最古老而且最大的行业。以生物工程学为基础的食品产品和工艺的进一步发展取决于目前工艺的改进,例如,发酵技术,固定化生物催化剂技术以及添加剂和加工助剂的生产,同时也取决于食品生物工程学新的机会的发现。在食品原料(food material)的特性、安全性和质量控制方面,在加工方法上,在废物转化和利用工艺方面,在目前所使用的食品微生物和组织培养系统中,需要作很多改进。还需要对食品原料的结构-功能关系和生物原料(raw material)的细胞生理学和生物化学进行基础研究。     

Exploitation of biological wastes for the production of value-added products under solid-state fermentation conditions

Biological wastes contain several reusable substances of high value such as soluble sugars and fibre. Direct disposal of such wastes to soil or landfill causes serious environmental problems. Thus, the development of potential value-added processes for these wastes is highly attractive. These biological wastes can be used as support-substrates in solid-state fermentation (SSF) to produce industrially relevant metabolites with great economical advantage. In addition, it is an environmentally friendly method of waste management. This paper reviews the reutilization of biological wastes for the production of value-added products using the SSF technique.     

微生物在有机固废堆肥中的作用与应用

好氧堆肥是实现有机固体废弃物资源化利用的主流处理方式。堆肥腐熟是一个由微生物主导的生理生化过程,堆料通过微生物发酵实现矿质化、腐殖化和无害化,转变成腐熟的有机肥。传统的好氧堆肥存在发酵周期长、养分损失、恶臭及温室气体排放等不足。在堆肥过程中添加微生物是弥补传统好氧堆肥缺陷、提高堆肥品质和功效的有效方法。近年来,国内外在好氧堆肥过程中主要微生物类群与其演替规律、外源添加微生物的作用与功能等方面取得了较大进展。本文简述好氧堆肥基本过程与主要影响因素,以及这个过程中主要微生物类群与其演替规律,重点介绍有关微生物添加剂在好氧堆肥中的应用及其作用方面的研究进展。同时,我们对目前微生物添加剂在应用中存在的问题进行分析并对解决途径进行探讨。     

柑橘果实加工废料资源化新技术研究

本文报道柑橘果实加工废料经直接压榨,并利用微生物发酵制取乙醇、橙皮甙及饲料等新技术。乙醇、橙皮甙产品经检验达A.R.级;饲料中脂肪、蛋白质含量分别比发酵前提高了175.7%和51.1%。制备全过程不产生污染,便于产业化。     

Production of bacterial exopolysaccharides by solid substrate fermentation

In a comparison of submerged cultivation (SC) with solid substrate fermentation (SSF) for the production of bacterial exopolysaccharides (EPS), the latter technique yielded 2 to 4.7 times more polymer than the former, on the laboratory scale. SSF was performed using inert solid particles (spent malt grains) impregnated with a liquid medium. The polymer yields obtained from SSFs, as referred to the impregnating liquid volumes, were as follows: 38.8 g/litre xanthan from Xanthomonas campestris, 21.8 g/litre succinoglycan from Rhizobium hedysari and 20.3 g/litre succinoglycan from Agrobacterium tumefaciens PT45. These results make this technique promising for a potential application on the industrial scale. A further advantage with this fermentation process is found in the availability and low cost of substrates, which are obtained as by-products or wastes from the agriculture or food industry.     

Enzyme Production of the Edible Mushroom Pleorotus ostreatus in Shaken Cultures Completed with Agro‐Industrial Wastes

The enzyme production of the white‐rot fungus, the edible mushroom Pleurotus ostreatus, was determined in shaken culture media containing extracts of agro‐industrial wastes (tomato, potato and pepper residues) as an unique carbon source. The activity of β‐glucosidase, xylanase, laccase as well as manganese‐dependent and independent peroxidases was measured at 0, 3.5, 7.0, 10.5, 14.0, 17.5, 21.0, 24.5, 28.0 and 31.5 days of cultivation. A spectral mapping technique and non‐linear mapping were employed for the calculation of the relationships among the fermentation parameters, such as fermentation time, enzyme activity and selectivity of enzyme production. It was established that P. ostreatus produced β‐glucosidase, xylanase, laccase, manganese‐dependent and independent peroxidases in each culture medium and that the enzyme activities were higher in cultures containing agro‐industrial wastes than in the control containing glucose as a carbon source. The spectral mapping technique allowed demonstrating that the enzyme activities were the highest in the culture completed with pepper extract followed by cultures containing potato and tomato extracts. The differences among the selectivity of the enzyme activities were negligible up to 21.0 days of fermentation and reached the maximum at the end of the fermentation process. The production of laccase as well as manganese‐dependent and independent peroxidases showed similar patterns while the selectivity patterns of xylanase and β‐galactoside production were different. In addition, it became evident that the agro‐industrial wastes influenced the enzyme production in a distinct way.     

Direct production of L+-lactic acid from starch and food wastes using Lactobacillus manihotivorans LMG18011

This study describes several essential factors for direct and effective lactic acid production from food wastes by Lactobacillus manihotivorans LMG18011, and optimum conditions for simultaneous saccharification and fermentation using soluble starch and food wastes as substrates. The productivity was found to be affected by three factors: (1) initial pH, which influenced amylase production for saccharification of starch, (2) culture pH control which influenced selective production of L(+)-lactic acid, and (3) manganese concentration in medium which improved in production rate and yield of lactic acid. The optimum initial pH was 5.0-5.5, and the fermentation pH for the direct and effective fermentation from starchy substrate was 5.0 based on the yield of L(+)-lactic acid. Under these conditions, 19.5 g L(+)-lactic acid was produced from 200 g food wastes by L. manihotivorans LMG18011. Furthermore, the addition of manganese stimulated the direct fermentation significantly, and enabled complete bioconversion within 100 h.     

Anaerobic waste digestion in Germany – Status and recent developments

Anaerobic treatment processes are especially suited for the utilization of wet organic wastes from agriculture and industry as well as for the organic part of source-separated household wastes. The anaerobic degradation is a very cost-effective method for treating biogenic wastes because the formed biogas can be used for heat and electricity production and the digester residues can be recycled to agriculture as a secondary fertilizer. The anaerobic technology will be used today also for the common treatment of wastes together with renewable energy crops in order to reduce the CO₂-emissions according the Kyoto protocol. Various process types are applied in Germany which differ in material, reaction conditions and in the form of the used reactor systems. The widespread introduction of anaerobic digestion in Germany has shown that biogenic organic wastes are a valuable source for energy and nutrients. Anaerobic waste treatment is done today in approx. 850 biogas plants on small farm scale as well as on large industrial scale with the best beneficial and economic outcome. Due to some new environmental protection acts which promote the recycling of wastes and their utilization for renewable energy formation it can be expected that several hundreds new biogas plants will be built per year in Germany. For using the synergetic effects of a combined fermentation of wastes and energy crops new process types must be developed in order to optimize the substrate combinations and the process conditions for maximum biodegradation.     

Valorisation of solid biowastes: The lactic acid alternative

Solid biowastes (SBW) are organic residues from gardens and parks, food wastes from kitchens, organic municipal solid wastes and comparable side streams from food processing plants. Without proper treatment, SBW represent an environmental hazard. Several initiatives around the world are dedicated to developing more effective systems for the treatment of this constantly growing ‘resource’. The chemical composition of SBW, rich in carbohydrates, proteins and lipids, makes it a good substrate to produce biobased materials through fermentation. Amongst them, lactic acid (LA), considered one of the top ten green molecules of the future, has attracted huge interest because of its many uses as an intermediate chemical. This review gathers the most important learnings from fermentation of SBW to LA, providing an overview of the process steps while highlighting some of the current limitations to overcome. Despite their complexity, results suggest that some of the SBW could be good substrates in LA fermentations and that biosynthesis of LA should be regarded as part of the whole waste management solution.     

Bioconversion of lignocellulosic waste from selected dumping sites in Dar es Salaam,Tanzania

The poor management of solid wastes in Tanzania urban centers is a chronic problem that has increasingly become a source of environmental pollution. Bioconversion offers a cheap and safe method of not only disposing these wastes, but also it has the potential to convert lignocellulosic wastes into usable forms such as reducing sugars that could be used as food. This paper reports a preliminary study on the physical characteristics, acid pretreatment, saccharification by cellulase from Trichoderma reesei and fermentation by Saccharomyces cerevisiae of the lignocellulosic component of the solid wastes collected from various dumping sites located in Kinondoni Municipality, Dar es Salaam city. The results showed that overall, the lignocellulosic component constitute about 50% of solid wastes dumped in the study areas. Maximum production of reducing sugars was obtained after 6 h of saccharification while highest concentrations of bioethanol were achieved after 48 h of fermentation. Microbial bioconversion of lignocellulose component yielded up to 21% bioethanol.     

Management of soybean oil refinery wastes through recycling them for producing biosurfactant using Pseudomonas aeruginosa MR01

Biosurfactant production through a fermentation process involving the biodegradation of soybean oil refining wastes was studied. Pseudomonas aeruginosa MR01 was able to produce extracellular biosurfactant when it was cultured in three soybean oil refinement wastes; acid oil, deodorizer distillate and soapstock, at different carbon to nitrogen ratios. Subsequent fermentation kinetics in the three types of waste culture were also investigated and compared with kinetic behavior in soybean oil medium. Biodegradation of wastes, biosurfactant production, biomass growth, nitrate consumption and the number of colony forming units were detected in four proposed media, at specified time intervals. Unexpectedly, wastes could stimulate the biodegradation activity of MR01 bacterial cells and thus biosurfactant synthesis beyond that of the refined soybean oil. This is evident from higher yields of biodegradation and production, as revealed in the waste cultures (Y_{deg|(Soybean oil)} = 53.9 % < Y_deg|(wastes) and Y_P/S|(wastes) > Y_{P/S|(Soybean oil)} = 0.31 g g^?1, respectively). Although production yields were approximately the same in the three waste cultures (Y_P/S|(wastes) ? 0.5 g g^?1), microbial activity resulted in higher yields of biodegradation (96.5 ± 1.13 %), maximum specific growth rate (μ _max  = 0.26 ± 0.02 h^?1), and biosurfactant purity (89.6 %) with a productivity of 14.55 ± 1.10 g l^?1, during the bioconversion of soapstock into biosurfactant. Consequently, applying soybean oil soapstock as a substrate for the production of biosurfactant with commercial value has the potential to provide a combination of economical production with environmental protection through the biosynthesis of an environmentally friendly (green) compound and reduction of waste load entering the environment. Moreover, this work inferred spectrophotometry as an easy method to detect rhamnolipids in the biosurfactant products.