污泥丝状膨胀及控制对策

本文在分析污泥膨胀的发生机理的前提下,阐述引起污泥膨胀的主要原因：污泥负荷、溶解氧、pH值、温度等;并提出控制污泥膨胀的一些措施：调节反应池中的溶解氧及pH值,投加营养盐合理调配营养比等。     

反应器形式及污泥形态对厌氧氨氧化菌群落结构的影响

通过构建克隆文库,对反应器类型和污泥形态对厌氧氨氧化（anammox）细菌的群落结构的影响进行探索. 研究发现,反应器类型对anammox细菌群落结构影响不大,但其种泥来源对功能细菌的群落结构有一定影响. 污泥形态对anammox细菌群落结构有着重要影响,絮体污泥中的anammox细菌以Candidatus Kuenenia为主;聚集态污泥中的anammox细菌则以Candidatus Brocadia为优势菌;在同时存在絮体污泥和生物膜的复合式反应器中,不同污泥形态中anammox细菌在接触时会发生迁移,但其优势菌种不发生变化.     

废水中硫酸盐生物处理原理与工艺

废水生物脱硫工艺成本低、效率高、污染少,且可以回收单质硫,具有较高的经济价值,因此受到污水处理领域的广泛关注。本文详细介绍了硫酸盐废水的生物处理技术,主要关注其处理原理,特别是功能菌—硫酸盐还原菌的种类和代谢途径,以及单相吹脱工艺、两相厌氧工艺、生物膜法工艺、硫酸盐还原与硫化物光合氧化联用工艺、微好氧工艺、两相厌氧与硫化物生物氧化联用工艺、同步脱氮除硫工艺等多种目前传统和新型生物脱硫工艺。     

High arsenic tolerance in Brevundimonas aurantiaca PFAB1 from an arsenic-rich Indian hot spring

BackgroundArsenic contamination in the ground water of rural India is a recurrent problem and decontamination is mostly based on the chemical or physical treatments until now. Microbial bioremediation is eco-friendly, cheap, time-efficient and does not produce any toxic by-products.ResultIn the present study, a high arsenic tolerant bacteria Brevundimonas aurantiaca PFAB1 was isolated from Panifala hot spring located in West Bengal, India. Previously Panifala was also reported to be an arsenic-rich hot spring. B. aurantiaca PFAB1 exhibited both positive arsenic reductase and arsenite oxidase activity. It was tolerant to arsenite up to 90 mM and arsenate up to 310 mM. Electron microscopy has proved significant changes in cellular micromorphology and stalk appearance under the presence of arsenic in growth medium. Bioaccumulation of arsenic in As (III) treated cells were 0.01% of the total cell weight, while 0.43% in case of As (V) treatment.ConclusionsAll experimental lines of evidence prove the uptake/accumulation of arsenic within the bacterial cell. All these features will help in the exploitation of B. aurantiaca PFAB1 as a potent biological weapon to fight arsenic toxicity in the near future.How to cite: Banerjee A, Sarkar S, Gorai S, et al. High arsenic tolerance in Brevundimonas aurantiaca PFAB1 from an arsenic-rich Indian hot spring. Electron J Biotechnol 2021:52. https://doi.org/10.1016/j.ejbt.2021.05.006     

钾细菌的分离及对Cu^2＋的耐受性实验研究

利用分离培养基从草坪、芦苇地、公园以及菜园土壤中分离到一株高效钾细菌菌株,经纯化后,研究了钾细菌对铜的耐受阈值,并筛选了提高钾细菌Cu^2＋耐受阈的钝化剂。结果表明,钾细菌最高能耐受Cu^2＋的浓度为50mg/L。投加钝化剂粉煤灰和石灰后,钾细菌对Cu^2＋的耐受阈提高到80mg/L,粉煤灰对重金属铜的钝化性能优于石灰。     

凉州熏醋大曲中细菌区系研究

研究了凉州熏醋传统酿造大曲中细菌区系,对大曲中的细菌总数、醋酸菌、乳酸菌及耐热菌进行计数、分离纯化和鉴定,通过显微镜镜检、革兰氏染色、接触酶反应、需氧型、产酸产气、发酵性等特性测定,对分离的菌株进行了具体菌属鉴定.结果表明,大曲表面与大曲中心细菌区系差异明显;大曲中共分离到5株醋酸菌、8株乳酸菌和4株耐热菌;醋酸菌分属为醋杆菌属和葡糖杆菌属;乳酸菌分属为糖球菌属、链球菌属、魏斯氏菌属、乳球菌属和索丝菌属;耐热菌分属为微球菌属和芽孢杆菌属.     

ICU感染病原菌的检出率及其耐药性分析

目的：回顾性的分析某医院重症监护室（ICU）2012年1月1日至2012年12月31日之间感染病原菌的分布及其耐药情况。方法：用VITET-2Compact60全自动微生物分析仪鉴定细菌,K—B纸片扩散法做体外药敏试验,统计、分析细菌的检出率和药敏结果。结果：799份ICU标本,医院感染分离菌株249株,检出率31．16％。首位是洋葱伯克霍尔德菌（60株,24．10％）,其次鲍曼不动杆菌（55株,22．09％）,第三是肺炎克雷伯菌（39株,15．66％）。分离菌中标本来源痰和咽拭子最常见,其次静脉血、静脉导管。洋葱假单胞、鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌、大肠埃希菌、人葡萄球菌及金黄色葡萄球菌对多种抗菌药物均具有较高的耐药性。结论：医院感染病原菌中以非发酵菌的检出率最高,其次是肺炎克雷伯菌并且耐药性强。因此治疗医院感染病原菌所致的感染性疾病应根据体外药敏试验结果选用敏感的抗菌药物,减低耐药率。     

一株脱硅胶质芽孢杆菌的分离与初步鉴定

本文利用无氮铝硅酸盐矿物选择性培养基，从土壤、铝土矿等样品中分离得到10株产荚膜的芽孢杆菌。对其中编号为GSY-1的菌株的生物脱硅试验结果表明：在pH7．2，30℃，200r／min后，矿浆含量5％，浸出时间7d，铝土矿矿样的A／S从10．30提高到13．48，增幅达30．87％，差异显著，由此确定该菌株具有一定的铝土矿脱硅能力。通过对GSY-1菌株的细胞形态、培养条件及生理生化特征的测定并与模式株对照，可初步鉴定为硅酸盐胶质芽孢杆菌。     

不同品种香菇菌棒蛋白质与多糖含量的比较研究

碱浸提法提取S604、S606、931、中7、808、808对照、868、135、908、9015、939等11种香菇菌棒中的蛋白质和多糖,结果表明：135和908的蛋白质含量显著高于其他9个品种,9015的多糖含量显著高于其他10个品种。     

Mycorrhizoremediation an enhanced form of phytoremediation

Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi （AMF） are universal and ubiquitous rhizosphere mi- croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal （HM） contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial biotechnology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.