Insights into the changes of amino acids,microbial community,and enzymatic activities related with the nutrient quality of product during the composting of food waste

● The highest seed germination index was achieved at 0.3 g/g total solids of food waste. ● Proline was identified as the key amino acid related with the composting process. ● Amino acid metabolism sequences predominated during the whole composting process. This study systematically investigated the changes of amino acids as the composting process of food waste proceeded. It is found that the addition of 0.3 g/g total solids of food waste achieved the highest seed germination index of the product (268 %). The microbial community results indicated that the abundance of amino acid metabolism sequences remained at high levels during the whole composting process. Proline was identified as the key amino acid related with the nutrient quality of product during the composting of food waste. Further plant germination and hydroponic experiments found, that compared with those without the addition of proline, the addition of 50 mg/L proline increased seed germination rate by 20 %, increased shoot length by 3 %, increased root biomass of seedlings by 82 %, and increased leaf biomass of seedlings by 76 %, respectively. Firmicutes, γ-Pseudomonadota, Chloroflexi and Planctomycetes were the key identified bacteria related with the increase of proline during the composting of food waste. Meanwhile, the enzymatic tests of the activities of superoxide dismutase, peroxidase and malondialdehyde indicated that proline did not cause oxidative damage on the growth of plants. This study provided novel insights into the changes of amino acids, microbial community, and enzymatic activities related with the nutrient quality of product during the composting of food waste.     

增加污水中挥发性脂肪酸以提高生物除磷效果的研究进展

VFA（挥发性脂肪酸）是生物除磷过程中的关键物质,并且不同VFA对生物除磷效果的影响也不相同。本文介绍了提高污水中VFA含量的几种方法,这些方法包括直接加入VFA、通过发酵污水产生VFA、发酵污水和初沉污泥产生VFA、发酵初沉污泥以及发酵初沉污泥和剩余污泥的混合物产生VFA等几种方法来提高生物除磷效率。目前国内外以发酵初沉污泥产生VFA的研究和应用较多。     

半导体材料生产废水中的GaAs、Ga3+和Ge4+对活性污泥核酸和氨基酸的影响

研究了GaAs、Ga³⁺、Ge⁴⁺、Hg²⁺和Cr⁶⁺对活性污泥脱氧核糖核酸(DNA)和核糖核酸(RNA)的影响,以及GaAs对活性污泥氨基酸的影响。结果表明,Hg²⁺和Cr⁶⁺主要使活性污泥中核酸的DNA含量减少,GaAs则主要使RNA含量减少,Ge⁴⁺浓度达到300ppm/g MLSS对,无论对DNA还是RNA的合成都有较强的抑制影响。低浓度的GaAs对活性污泥氨基酸含量影响不大,而GaAs浓度达360ppm/g MLSS时则使活性污泥中氨基酸含量明显减少。     

大熊猫肌肉氨基酸含量的初步研究

测定了３只大熊猫的头部、背部和腿部等１０个肌肉样品中１７种氨基酸（ＡＡ）含量,并分析了各样品ＡＡ与Ｌｙｓ含量的比值．结果表明：对同一只大熊猫,不同部位的肌肉样品中各ＡＡ含量无明显差异;对同一个肌肉样品,１７种ＡＡ含量比较,Ｇｌｕ含量最高,Ａｓｐ、Ａｒｇ、Ｌｙｓ、Ｌｅｕ、Ａｌａ、Ｇｌｙ、Ｖａｌ、Ｐｒｏ、Ｔｈｒ、Ｐｈｅ等含量较高;不同年龄大熊猫肌肉ＡＡ含量有差异,除极少数ＡＡ外,未成熟雄性大熊猫肌肉ＡＡ含量高于成熟和老龄雌性大熊猫,且有显著性差异（Ｐ＜０．０５或Ｐ＜０．０１）;成熟雌性大熊猫肌肉中,除Ｐｒｏ外,其余所有ＡＡ含量与其年龄无显著差异（Ｐ＞０．０５）;除极少数ＡＡ外,不同年龄、性别大熊猫肌肉样品中各ＡＡ与Ｌｙｓ含量的比值无明显差异     

Organic composition in the dry season rainwater of Guangzhou, China

This paper reports the results from a study of the organic composition of rainwater collected at Tianhe district of Guangzhou city, P.R. China, during the dry season. Several special setups of a pyrex bottle with a glass funnel were used for the collection of the rainwater. Three fractions (aliphatics, PAHs and fatty acids) were separated from the total extracted organic compounds and identified with GC-MS. The molecular diagnostic ratios were utilized for the source reconciliation. The aliphatic hydrocarbon and the biomarkers (triterpanes and steranes) distribution show a characteristic of the petrochemical source in the rainwater samples. The PAHs diagnostic ratios [e.g. MP/P, MPI, Fl/ (Fl + Py)] indicated vehicular emissions. The fatty acids ratios (e.g. C_18:1/C_18:0 and C_18:2/C_18:0) reflect the contribution of cooking emissions, while the higher plant waxes play little part. Moreover, the values of MP/P, MPI, BaA/(BaA + CT) and BeP/(BeP + BaP) reflected the origin of the long-distance transportation to some extent. On the whole, for the dry season rainwater, all molecular diagnostic ratios indicated the complexity of the organic composition of the rain, which have the characteristics of both a local emission contribution and a long-distance transportation contribution.     

Characteristics of organic acid profiles in 16 species of wild growing edible mushrooms

The aim of study was to determine 9 organic acids in nine aboveground and seven wood-growing wild edible mushroom species originated from an area under the direct influence of a busy trunk road in Poland. The organic acids in the extracts of samples were identified by reversed-phase column liquid chromatography (RPLC). The presented results show that all the mushroom species were characterized by high variation in the profile and content of the analyzed acids. Each of mushroom species contained oxalic acid, the profiles of the other acids strictly depended on mushroom species. Among aboveground species, the highest total content of organic acids was found in Lepista gilva (267.5 ± 26.6 mg g^?1 dry weight (DW)), while Laccaria amethystina was characterized by the lowest content (37.7 ± 6.5 mg g^?1 DW). Within wood-growing species, the highest content of organic acids was determined in Flammulina velutipes (171.9 ± 26.7 mg g^?1 DW), whereas the lowest content (34.2 ± 2.9 mg g^?1 DW) of the studied acids was observed in Grifola frondosa.     

Hollow-fiber liquid-phase microextraction based on carrier-mediated transport for determination of urinary methyl hippuric acids

Hollow-fiber liquid-phase microextraction based on carrier-mediated transport for analysis of methyl hippuric acids in aqueous samples is described. Under optimized conditions, relative recoveries of 83%–98% and limits of detection of 2–3 µg L^?1 were obtained, with linear calibration curves for the three isomers in the range of 10–50,000 µg L^?1. The method was applied for the determination of urine samples of volunteers at various working environments.     

OPA柱前衍生-反向高效液相色谱法测定水中游离氨基酸

采用邻苯二甲醛柱前衍生5种氨基酸,用反向高效液相色谱法测定衍生化产物,通过优化衍生化条件和色谱条件,使该方法在0.25μmol/L~25μmol/L范围内线性良好。方法检出限为0.08μmol/L~0.12μmol/L,标准溶液测定6次的RSD为0.1%~1.2%,空白加标样的回收率为80.3%~115%。用该方法测定实际水样,5种氨基酸测定值均低于0.514μmol/L,加标回收率在75.5%~120%之间。     

MBR处理医院污水后续氯消毒及其消毒副产物研究

针对医院污水中致病微生物的特殊排放要求,研究了膜生物反应器（MBR）应用于医院污水处理中的预消毒及其后续氯消毒特性.结果表明,在工程应用中MBR具有显著的预消毒作用,对医院污水中的细菌总数和粪大肠杆菌的去除率分别达到2.0～3.1 lg和2.8～4.0 lg;对于MBR出水中残留的微生物,采用次氯酸钠进行后续消毒,当接触时间为1 h,在有效氯浓度为0.8 　mg/L时,可检测不出粪大肠杆菌,且放置6 h未见再生长,相应的THMs和HAAs分别为16.94 μg/L和32.10 μg/L;固定接触时间,随着Cl₂/DOC值的增加,MBR出水中THMs和HAAs均近似呈线性增长趋势（r²分别为0.941?5和 0.965?2）,且HAAs的增长速率高于THMs.