Lactobacillus plantarum ZLC-18 fermentation improve tyrosinase inhibition activity and antioxidant capacity in soybean hulls

Soybean hulls, the main byproduct in soybean processing, have many biological activities. However, the value of this byproduct is still far from being fully exploited. In this study, we investigated the anti-tyrosinase and antioxidant capacities in soybean hulls fermented by Lactobacillus plantarum ZLC-18 (L. plantarum ZLC-18). We found that L. plantarum ZLC-18 fermentation could markedly improve the anti-tyrosinase and antioxidant activities of soybean hulls. The anti-tyrosinase and antioxidant activities were positively correlated with the total phenolic and flavonoid contents. UPLC–MS analysis suggested that phenolic compounds (daidzin, genistin, vanillic acid and so on) were increased in soybean hulls after fermentation, and some of these compounds were shown to have anti-tyrosinase and antioxidant activities. Our study demonstrates that fermentation is an efficient strategy to enhance the bioactive function of soybean hulls. Moreover, this study provides evidence that soybean hulls can be used as a kind of functional food ingredient, thereby improving their economic benefits.     

Effects of rice bran fermented with Lactobacillus plantarum on palatability,volatile profiles,and antioxidant activity of brown rice noodles

Brown rice noodles (RN) are typical whole-grain products with health benefits. This study investigated the effects of rice bran fermented with Lactobacillus plantarum on palatability, volatile profiles, and antioxidant activity of brown RN. Three kinds of RN, including RN, brown RN (BRN), and bran fermented RN (BFRN), were involved in this study. The results indicated that bran fermentation reduced the cooking loss of BFRN and improved the elongation and the sensory attributes of brown RN. After fermentation, aldehydes were significantly decreased while alcohols increased, and more pleasant flavours were shown in BFRN. Fermentation increased the content of free phenolics and decreased the content of bound phenolics. Among the four major phenolics detected in this study, ferulic acid was the most abundant one in all three RN samples. The DPPH radical scavenging activity and the ferric reducing antioxidant power of free phenolics in BFRN increased significantly compared to BRN. This study proved that rice bran fermentation is an effective approach to improve palatability, enrich the flavour as well as enhance the antioxidant activity of brown RN, which may facilitate the development of processing technology for brown RN.     

Promoting dark fermentation for biohydrogen production: Potential roles of iron-based additives

Dark fermentation (DF) is a promising technology for biohydrogen production. Low efficiency of biohydrogen production is a bottleneck of the scale-up prospects for DF. Additives have been extensively studied to improve the biohydrogen production efficiency. Among of them, iron-based additives present a promising application potential due to their demonstrated significant enhancement of DF efficiency and among the low-cost bioactive agents. However, current reviews mainly examined the effects of nano-materials on DF and an in-depth analysis of enhancing mechanisms with addition of iron-based additives in DF is still lacking. To this end, this article comprehensively reviewed and evaluated the effects of iron-based additives on DF. Further, the potential mechanisms, including altering metabolic pathways, improving activities of microbes and enzymes, promoting electron delivery, and enriching hydrogen-producing bacteria, were discussed. Lastly, prospects and challenges of iron-based additives for subsequent research and large-scale application for DF were summarized.     

高密度氧化亚铁钩端螺菌的培养研究

研究了氧化亚铁钩端螺菌(Leptospirillums ferrooxidans)发酵罐补料连续培养的最佳条件。结果表明:pH为1.2,接种量为33%(V/V),充气量为6 L/min,搅拌转速为450 r/min时,培养30 h后,用3 mL/min的速度补料,补料1 500 mL后,菌密度可达1.0×1010个/mL,高于文献报道。     

生物质能利用技术及研究进展

对生物质能的概念、利用生物质能的意义及生物质能的转化利用方式进行了介绍。生物质能转化方法分为生物化学转化(发酵和消化)、热化学转化(直接燃烧、气化、热解和液化)、机械萃取等。     

Performance characteristics of the anaerobic baffled reactor

An anaerobic sludge blanket process, termed the anaerobic baffled reactor (ABR), has been developed and shows promise for industrial wastewater treatment. It combines the advantages of high stability and reliability with a high void volume. The risk of clogging and sludge bed expansion with resulting high microbial losses is reduced and there is no need for special gas collection or biological solids separation systems. Organic loadings as high as 36 g COD l^?1day^?1 have been achieved with COD removal rates of more than 24 g COD l^?1 day^?1 and methane production rates exceeding 6 volumes per day per unit volume of reactor. The hypothesis, that the ABR may be adequately modeled as a fixed-film reactor, has been supported. Therefore, a unified approach, based on fundamentals of bacterial kinetics and mass transport, appears useful for modeling this and similar systems. Pilot plant studies are necessary to determine the scaling factors of the system as well as the overall efficiency and costs.     

复合型微生物絮凝剂的开发

首次提出了复合型微生物絮凝剂这一概念，即采用廉价底物经过多株菌混合发酵后制得的微生物絮凝剂。发酵过程中采用的菌种取自活性污泥和土壤，分离筛选出的4株絮凝率较高的菌株经鉴定均为芽孢杆菌属。把其中任意两株混合培养之后，发现F2和F6发酵液的絮凝率较原来的单株菌均有提高，因此这两株菌成为后续发酵的主要菌种。通过摇床试验确定了制取该絮凝剂的发酵条件，并就其对源水的处理效果作了测定。     

钢渣微粉对牛粪厌氧发酵产沼气的影响

为提高沼气发酵效率和沼气产量,以不同钢渣微粉作为沼气发酵的功能促进剂,探讨其对牛粪厌氧发酵的沼气产量、发酵前后pH值和发酵前后COD值的影响。结果表明：钢渣微粉对牛粪厌氧发酵产沼气具有显著的促进作用,不仅能够提高原料的累积产气量和产气速率,而且能使产气高峰期大幅提前,其中0.5% ZHB钢渣微粉对牛粪厌氧发酵产沼气效果最佳;钢渣微粉明显提高发酵前各处理组的pH值;钢渣微粉有助于提高厌氧发酵的COD值降低率,其中0.5%的ZHB钢渣微粉总COD值降低率达到64.74%,同时可以促使发酵启动最快,效率最高,周期最短。