降解木片树脂的白腐菌菌种选育与脱除树脂过程

通过在自然界采集、室内平板初筛及平板变色反应复筛得到了20株白腐菌菌株，并对变色系数最小的一株菌株G进行松木片固体接种实验。测定经2种不同浓度无机盐稀释的菌悬液接种松木片3天、5天、7天、9天后的木紊、树脂降解情况。结果显示，随着接种时间增加，松木片失重率逐渐增大，Klason木素、酸溶木素和总木紊含量逐渐下降，苯-醇抽出物和二氯甲烷抽出物含景也逐渐减少。表面扫描电镜照片表明，接种白腐菌的木片细胞壁上产生了明显的腐朽沟槽等现象；白腐菌菌丝在木片表面的生长呈由少到多、由凌乱到较有规律排列；松木片切片断面显微结构显示菌丝在细胞壁部位及胞间层也开始出现，这说明菌丝开始向细胞内部渗透。     

红茶菌酒饮料的研究

本文研究了红茶菌酒饮料的生产方法:以酵母菌、醋酸菌和乳酸菌为工作菌种,用糖、茶作为营养成分,在菌种互为条件,共同生存的情况下产生代谢产物;然后以发酵茶菌液为基液,加入一定数量的基酒,制成一种酒饮料。实验结果表明:红茶菌酒饮料酸甜适宜,既具茶的清香,也具有酒的清香,营养丰富、风味独特,有利于吸收,对人体有一定的营养价值和医疗保健作用。     

Mercury in fruiting bodies of dark honey fungus (Armillaria solidipes) and beneath substratum soils collected from spatially distant areas

BACKGROUND: This paper reports data on bioconcentration potential and baseline mercury concentrations of fruiting bodies of dark honey fungus (Armillaria solidipes) Peck and soil substrate layer (0–10 cm) from 12 spatially distant sites across Poland. Mercury content of caps, stipes and soil samples were determined using validated analytical procedure including cold‐vapor atomic absorption spectroscopy after thermal decomposition of the sample matrix and further amalgamation and desorption of mercury from gold wool. RESULTS: Mean mercury concentrations ranged from 20 ± 8 to 300 ± 70 ng g^?1 dry weight (dw) in caps, from 20 ± 6 to 160 ± 40 ng g^?1 dw in stipes, and in underlying soil were from 20 ± 2 to 100 ± 130 ng g^?1 dw. The results showed that stipes mercury concentrations were 1.1‐ to 1.7‐fold lower than those of caps. All caps and the majority of stipes were characterized by bioconcentration factor values > 1, indicating that dark honey fungus can be characterized as a moderate mercury accumulator. CONCLUSION: Occasional or relatively frequent eating of meals including caps of dark honey fungus is considered safe in view of the low total mercury content, and the mercury intake rates are below the current reference dose and provisionally tolerable weekly intake limits for this hazardous metal. © 2012 Society of Chemical Industry     

Characterization and Classification of Streptococcus Thermophilus and Lactobacillus Delbrueckii Subsp. Bulgaricus Strains Isolated from Traditional Greek Yogurts

ABSTRACT Streptococcus thermophilus (74 strains) and Lactobacillus delbrueckii subsp. bulgaricus (75 strains) isolates from traditional Greek yogurts were tested on the basis of their acidification kinetics, acidity, viscosity, and aroma compounds formation in milk pure cultures. Strains of Lb. bulgaricus presented greater viscosity values, higher acidification activity and produced more acetaldehyde at culture pH 4.6 than S. thermophilus strains. Acetoin was formed only by the latter strains, while diacetyl was not detected in either species. Application of cluster and discriminant analysis permitted definition of distinct groups of strains and of the most significant variables to discriminate among them. Finally, classification and regression tree analysis allowed clusters characterization by critical values of the most discriminant variables. Evaluation of results as above could be a useful tool to select, through a large number of screened strains, the suitable starters for specific purposes.     

Fermentative biohydrogen production II: Net energy gain from organic wastes

Several reports have demonstrated the feasibility of hydrogen production by dark fermentation (DF). However, most reports had resorted to mesophilic or thermophilic conditions to increase hydrogen yield, overlooking the energy input to the process and hence, loss of net energy gain. For net positive energy gain, energy input to the process should be minimized and additional energy should be harvested from the aqueous end products of DF. Our previous study presented an approach to assess the potential for net energy gain from the hydrogen produced by DF, and from the end products of DF via anaerobic digestion (AD) or microbial fuel cells (MFC). In this study, that approach is extended to identify the most promising process configuration and operating conditions to maximize net energy gain possible from liquid and particulate organic wastes. Based on this analysis, DF followed by MFC appears to result in higher net energy gains.     

Plastic Degradation by Extremophilic Bacteria

Intensive exploitation, poor recycling, low repeatable use, and unusual resistance of plastics to environmental and microbiological action result in accumulation of huge waste amounts in terrestrial and marine environments, causing enormous hazard for human and animal life. In the last decades, much scientific interest has been focused on plastic biodegradation. Due to the comparatively short evolutionary period of their appearance in nature, sufficiently effective enzymes for their biodegradation are not available. Plastics are designed for use in conditions typical for human activity, and their physicochemical properties roughly change at extreme environmental parameters like low temperatures, salt, or low or high pH that are typical for the life of extremophilic microorganisms and the activity of their enzymes. This review represents a first attempt to summarize the extraordinarily limited information on biodegradation of conventional synthetic plastics by thermophilic, alkaliphilic, halophilic, and psychrophilic bacteria in natural environments and laboratory conditions. Most of the available data was reported in the last several years and concerns moderate extremophiles. Two main questions are highlighted in it: which extremophilic bacteria and their enzymes are reported to be involved in the degradation of different synthetic plastics, and what could be the impact of extremophiles in future technologies for resolving of pollution problems.     

PCB阻焊膜的功能

阻焊膜不仅起着阻焊作用,而且还起着防腐蚀、防潮湿和防霉菌的作用。     

基因工程菌在富营养化水体中应用的试验研究

该实验模拟了自然状况下水体富营养化的一般过程 ,利用基因工程菌消氮细菌及沉淀细菌对实验水体进行生物修复。得出结论 :在微生物处理下 ,水体的营养物质浓度不断降低 ,水体的浊度下降 ,透明度升高 ,使得实验水体的水质得到了明显的改善。     

白腐真菌对煤炭的降解转化试验

通过正交试验研究了白腐真菌在煤炭降解转化过程中煤样粒度、菌液用量、降解作用时间等各因素对其降解率的影响.还对白腐真菌对煤降解转化产物进行了元素分析，在此基础上探讨了白腐菌对煤生物降解转化的规律.实验结果表明，白腐真菌对经硝酸预处理后的义马褐煤样有较强的降解作用，15 d的时间能把粒度-0.2 mm的经硝酸预处理的义马褐煤降解41.54%，降解作用主要是白腐真菌在培养过程中释放出来的酶作用的结果.