餐厨垃圾生物发酵液对黄土丘陵区土壤质量的影响试验

黄土广泛分布于我国西北地区,因气候干旱和暴雨侵蚀等因素,土壤养分贫瘠、微生物量稀缺且盐碱化严重,限制了土壤生态承载力,是区域土地荒漠化主要成因之一.餐厨垃圾发酵产生的生物发酵液含有大量的有机酸和氮、磷等营养元素,并且可工业化生产和配施,有望成为一种针对黄土特性的土壤调理剂.以我国黄土高原代表性的甘肃兰州地区黄土为研究对象,采集不同发酵液配施后的黄土进行理化性质和微生物分析,发现施用发酵液后,黄土中全氮、有效磷、速效钾和有机质含量分别提升363%、577%、308%和204%;结合白茎盐生草和苜蓿等植被种植后,土壤综合肥力进一步提升,土壤全盐含量年均分别下降2.3 g·kg^-1和1.2 g·kg^-1;黄土的结构得到改善;发酵液能够促进部分微生物生长,细菌和古菌生物量提升了22倍,真菌生物量提升了8.3倍,有利于进一步形成植物-微生物共生体系.餐厨垃圾生物发酵液结合耐盐碱植物种植,能够有效提升黄土地区生态环境质量.     

制药行业高浓度有机废水的综合治理及资源利用研究

制药行业中的皂素生产废水,是酸性高浓度有机废水,富含淀粉水解产生的大量糖类,采用酸解和酒精生产工艺相结合的方法,从皂素废水中提取酒精,使废水中的有用资源得到再利用,不仅有良好的环境效益,亦产生明显的经济效益      

酒糟制取高蛋白菌体饲料优质菌种对碳源氮源利用率的研究

研究了8503和8505二白种在以白酒糟、薯干酒精糟及两糟混合的培养液中培养，对该酒糟培养液中还原糖的利用率和氮的转化率的分析检测方法．通过对绝于菌体质量的时变曲线与菌种对碳源利用率和氮源转化率的时变曲线的对比研究，可以看到该菌种在酒糟培养液中对碳源和氮源的利用率与转化率的规律性，经48h或72h发酵后碳源利用率可达90％左右，本实验最高达92．92％，氮源转化率一般可达50％～70％，本实验最高达68.41％，每100ml培养液中绝干菌体质量最高达0.78399。     

一株芽孢杆菌在低氮源浓度培养基中的生长与氨氮去除特性

对菌株YB3进行了16S rRNA基因序列进化分析,并分别以NH_4Cl、NaNO_2、NaNO_3、尿素和蛋白胨为单一氮源,配制了5种低氮源浓度培养基,研究YB3在与养殖水体相近营养水平条件下的生长与氨氮去除特性.结果显示,菌株YB3属于蜡样芽孢杆菌(Bacullis cereus),在5种培养基中均能够生长,菌悬液(吸光度OD600为1.0)接种量为1.0%(v/v)时,OD600由0.010增长到0.100~0.117.在NH_4Cl培养基中,YB3的氨氮去除速率为1.23 mg·L~(-1)·d~(-1),去除率为93.5%.在尿素、蛋白胨等有机氮源培养基中,YB3将首先导致氨氮的积累,累积倍数分别为51.69和3.38,之后开始去除,去除速率为1.56和0.29 mg·L~(-1)·d~(-1),去除率为93.7%和26.8%.结果也表明,提高YB3接种量至8.0%(v/v),可以使蛋白胨培养基氨氮累积倍数下降至2.02,去除速率提高至1.07 mg·L~(-1)·d~(-1),去除率最终达到98.4%.NaNO_2和NaNO_3培养基中均未检测到氨氮,而NH_4Cl、尿素和蛋白胨培养基中也未检测到NO_2~--N和NO_3~--N,表明YB3的硝化、亚硝化和反硝化作用均不强烈,去除氨氮的同时将不会造成NO_2~--N和NO_3~--N等的大量积累.本文为菌株YB3在养殖水体调控与净化中的应用研究提供了实验基础和理论支持.     

Isolation,identification, and biological characteristics of a wild Chaga mushroom北大核心CSCD

In this study, a pure culture strain (numbered as F1501) was obtained using tissue separation and purification methods from the sclerotia of Chaga mushroom from Russia. Further researches included studies on classification, optimum growth conditions of mycelia, extracellular polysaccharides from fermentation broth and their antioxidant activity, and artificial acclimation. According to the identification of the internal transcribed spacer (ITS) region, it was confirmed that F1501 was a species of the genus Inonotus and family Hymenochaetaceae, which had 99% similarity with Inonotus obliquus. F1501 was further classified as I. obliquus based on the morphological characteristics of its mycelia and sclerotia. The optimal carbon source, nitrogen source, C/N ratio, growth factor, temperature, and pH value for the growth of the F1501 strain mycelia were maltose, beef extracts, 10/1, B2, 28 °C, and 8.0, respectively. Liquid fermentation of F1501 was performed using PD media and a 10% inoculation amount at 28 °C and 150 r/min for 7 d. The content of polysaccharides in the fermentation broth was 476.32 mg/L, with a total antioxidant activity of 0.19 mmol/L (Trolox) and hydroxyl free radical-scavenging activity of 72.7%. Artificial acclimation study revealed that the fruiting body-like structure was obtained using cottonseed hulls as the main substrate. In the present study, a new strain of I. obliquus and its biological characteristics were explored, which could provide a theoretical basis for the artificial acclimation and development of wild mushrooms. © 2018 Science Press. All rights reserved.     

Dry-thermophilic anaerobic digestion of organic fraction of municipal solid waste: methane production modeling

The influence of particle size and organic matter content of organic fraction of municipal solid waste (OFMSW) in the overall kinetics of dry (30% total solids) thermophilic (55 °C) anaerobic digestion have been studied in a semi-continuous stirred tank reactor (SSTR). Two types of wastes were used: synthetic OFMSW (average particle size of 1 mm; 0.71 g Volatile Solids/g waste), and OFMSW coming from a composting full scale plant (average particle size of 30 mm; 0.16 g Volatile Solids/g waste).A modification of a widely-validated product-generation kinetic model has been proposed. Results obtained from the modified-model parameterization at steady-state (that include new kinetic parameters as K, Y_pMAX and θ_MIN) indicate that the features of the feedstock strongly influence the kinetics of the process. The overall specific growth rate of microorganisms (μ_max) with synthetic OFMSW is 43% higher compared to OFMSW coming from a composting full scale plant: 0.238 d⁻¹ (K = 1.391 d⁻¹; Y_pMAX = 1.167 L CH₄/gDOC_c; θ_MIN = 7.924 days) vs. 0.135 d⁻¹ (K = 1.282 d⁻¹; Y_pMAX = 1.150 L CH₄/gDOC_c; θ_MIN = 9.997 days) respectively.Finally, it could be emphasized that the validation of proposed modified-model has been performed successfully by means of the simulation of non-steady state data for the different SRTs tested with each waste.     

皂素生产废水的资源化综合利用实验

皂素生产废水是强酸性高浓度有机废水,富含淀粉水解后的糖类.据此特点,以皂素生产中的一次废水为原料,经中和处理后进行酒精发酵,使废水资源化.结果表明,采用工业氨水为中和剂,中和用量为5.20%(体积分数),发酵接种量为10%(体积分数),总发酵时间为60 h时,4 L废水可生产出95%的工业酒精120 mL.一次废水COD去除率达75%,后续废水量大大减少,具有明显的环境效益.经估算每生产lt工业酒精可处理4lt一次废水,与生产成本相比,具有明显的经济效益.     

延长初发酵培养时间对大肠菌群结果影响分析

阐述了将《大肠菌群多管发酵法》(GB/T 4789.28-2003)初发酵时间24 h延长至48 h的原因,通过对139份不同种类样品进行大肠菌群总数检测,发现有12份样品增加了大肠菌群数,表明延长初发酵培养时间,可以增加迟缓发酵大肠菌群成员检出.指出迟缓发酵大肠菌群在44.5 ℃培养时,均无产酸产气现象,表明引起迟缓发酵的大肠菌群不属于粪大肠菌群成员.     

Evaluation of recycling the effluent of hydrogen fermentation for biobutanol production: Kinetic study with butyrate and sucrose concentrations

Butyrate in the effluent of hydrogen-producing bioreactor is a potential feed for biobutanol production. For recycling butyrate, this study investigated the kinetics of biobutanol production by Clostridium beijerinckii NRRL B592 from different paired concentrations of butyrate and sucrose in a series of batch reactors. Results show that the lag time of butanol production increased with higher concentration of either sucrose or butyrate. In regression analyses, the maximum specific butanol production potential of 6.49 g g⁻¹ of dry cell was projected for 31.9 g L⁻¹ sucrose and 1.3 g L⁻¹ butyrate, and the maximum specific butanol production rate of 0.87 g d⁻¹ g⁻¹ of dry cell was predicted for 25.0 g L⁻¹ sucrose and 2.6 g L⁻¹ butyrate. The specific butanol production potential will decrease if more butyrate is added to the reactor. However, both sucrose and butyrate concentrations are weighted equally on the specific butanol production rate. This observation also is true on butanol yield. The maximum butanol yield of 0.49 mol mol⁻¹ was projected for 25.0 g L⁻¹ sucrose and 2.3 g L⁻¹ butyrate. In addition, a confirmation study found butanol yield increased from 0.2 to 0.3 mol mol⁻¹ when butyrate addition increased from 0 to 1 g L⁻¹ under low sugar concentration (3.8 g L⁻¹ sucrose). The existence of butyrate increases the activity of biobutanol production and reduces the fermentable sugar concentration needed for acetone–butanol–ethanol fermentation.     

Efficiency of physicochemical and biological treatments of vinasse and their influence on indigenous microbiota for disposal into the environment

Molasses-based distilleries are one of the most polluting industries generating large volumes of high strength wastewater called vinasse. Different processes covering anaerobic, aerobic as well as physicochemical methods have been employed to treat this effluent. This study evaluated the microbial communities present in the vinasse during different stages of its treatment by traditional and molecular methods. The analysis of the efficiency of each treatment was performed by physicochemical parameters and toxicity analysis. The treatment of vinasse was performed in the following steps: high flow fermentation; filtration; chemical flakes; low-flow fermentation; filtration; and neutralization. The physicochemical analysis in different stages of the vinasse treatment demonstrated that phases of treatment influenced the performance of the evaluated parameters. Among the 37 parameters, 9 were within the limits established by the Commission for Environmental Policy of Minas Gerais, Brazil (COPAM), especially BOD (96.7% of pollution reduction), suspended solids (99.9%), pH, copper (88%), iron (92.9%), and manganese (88%). Some parameters, even after treatment, did not fit the maximum allowed by legislation. The microbial population decreased reaching 3 log CFU/ml present in the steps of the flakes chemical and disinfection treatment of vinasse. Lactobacillus brevis and Pichia kudriavzevii were present in all stages of the treatments, showing that these microorganisms were resistant and demonstrated that they might be important in the treatment of vinasse. The vinasse showed a significant reduction of pollution load after the disinfection treatment however still should not be discarded into water bodies because the high values of tannins and sediment solids, but suggest the use of the effluent in the cooling coil during the distillation process of the beverage.