一株高效溶藻放线菌的分子生物学鉴定

实验室从土壤中分离筛选得到了一株具有高效溶藻能力的放线菌,命名为AN02。对这株具有高效溶藻效果能力的放线菌AN02分别进行了形态特征、培养特征及生理生化特性的分析,分析结果表明放线菌AN02菌株的上述几个特征与细黄链霉菌(Streptomyces microflavus)的高度一致,与此同时,聚类分析结果也同样表明,放线菌AN02菌株与细黄链霉菌(Streptomyces microflavus)的高度一致,后经过比对,发现二者的16SrDNA序列的同源性高达近100%,因此,可将溶藻放线菌AN02定名为细黄链霉菌AN02(Streptomyces microflavus AN02)。     

Screening for a new Streptomyces strain capable of e cient keratin degradation

Keratinous wastes could be degraded by some microorganisms in nature. Native human foot skin （NHFS） was used as sole nitrogen source to screen microorganisms with keratin-degrading capability. From approximately 200 strains, a strain of Streptomyces sp. strain No. 16 was found to possess the strongest keratinolytic activity, and the total activity in the culture was 110 KU/ml with specific activity of 2870 KU/mg protein （KU： keratinase unit）. Substrate specificity test indicated that the crude keratinase could degrade keratin azure, human hair, cock feathers and collagen. The optimal pH of the crude keratinase ranged from 7.5 to 10 and the temperature ranged from 40℃ to 55℃. Metal chelating agent ethylenediamine tetraacetic acid obviously stimulated the keratinolytic activity but suppressed the proteolytic activity. To our knowledge, this is the first report on specific induction of keratinases by NHFS from an actinomycete. Moreover, excellent characteristics of its crude keratinase may lead to the potential application in waste treatment and recovery, poultry and leather industry, medicine, and cosmetic development.     

Bioaccumulation characterization of uranium by a novel Streptomyces sporoverrucosus dwc-3

The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3, isolated from a potential disposal site for (ultra-)low uraniferous radioactive waste in Southwest China, were evaluated by using transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), proton induced X-ray emission (PIXE) and enhanced proton backscattering spectrometry (EPBS). Approximately 60% of total uranium at an initial concentration of 10 mg/L uranium nitrate solution could be absorbed on 100 mg S. sporoverrucosus dwc-3 with an adsorption capacity of more than 3.0 mg/g (wet weight) after 12 hr at room temperature at pH 3.0. The dynamic biosorption process of S. sporoverrucosus dwc-3 for uranyl ions was well described by a pseudo second-order model. S. sporoverrucosus dwc-3 could accumulate uranium on cell walls and within the cell, as revealed by SEM and TEM analysis as well as EDX spectra. XPS and FT-IR analysis further suggested that the absorbed uranium was bound to amino, phosphate and carboxyl groups of the cells. Additionally, PIXE and EPBS results confirmed that ion exchange also contributed to the adsorption process of uranium.     

Streptomyces avermitilis from marine

The insecticidal strain 173 was isolated from marine source and its activity was explored by the bioassay of brine shrimp and Helicoverpa armigera. Based on morphological, physiological and molecular properties, the insecticidal strain 173 was identified as Streptomycetes avermitilis, which is the best insecticidal microorganism found in the terrestrial environment. The taxonomy of the strain 173, insecticidal spectrum and properties of the corresponding insecticidal antibiotics are reported.     

一株耐酒精纤维素分解菌的分离鉴定及生长条件研究

木薯酒精糟因其低营养高含水量而难以利用和处理,目前对新鲜木薯酒精糟主要采用机械脱水及干燥的方法,但此类方法的经济成本和能耗都较高,很难形成产业化。该实验在木薯酒精糟中通过用刚果红培养基初筛和杜博氏培养基复筛得到一株耐酒精的纤维素分解菌,编为13号。经16S rRNA序列鉴定与链霉菌同源性达99%。其最适生长pH值为6.5,最适生长温度为40℃。对酒精有一定的耐受性,能在酒精浓度为6%的环境中生长,并且在酒精浓度为1%时对菌株生长影响不大。同时该菌能在40℃的温度条件下保持良好的生长态势,对适应废物堆肥发酵后期熟化产生有益次生代谢产物有利。所以利用此菌耐酒精、产纤维素酶且较耐高温等特性,对于处理含酒精的纤维素废物具有较好的应用前景。     

非活性菌丝体对水中铅离子的吸附

从发酵工业选取９种废弃的菌丝体,考察其对水中Ｐｂ离子的吸附行为。结果表明,其中半数菌丝体为Ｐｂ的最大吸附量接近或超过１００ｍｇ／ｇ干重,对林可链霉菌的吸附等温线和ｐＨ值、温度、共存离子等因素影响Ｐｂ离子吸附行为的研究表明,该菌丝体对Ｐｂ的吸附量随ｐＨ降低而升高,温度对吸附的影响不大,共存Ｃｕ＾２＋使Ｐｂ的吸附量降低,而共存Ｚｎ＾２＋无明显影响。     

林可霉素菌（Streptomyces lincolnensis）利用吡唑酮废水的研究

采用被吡唑酮废液驯化、分离、筛选后的林可霉素菌,并对其在摇瓶上利用吡唑酮废液中的硫酸铵发酵（7 d）生产林可霉素进行了研究。实验结果表明,废液加入培养基体积比都为1∶10,实验1中菌丝代谢和对照比正常,其中还原糖利用最快,在发酵后期为0.24 mg/L,林可霉素起步效价最低为2 100 IU/mL,与对照相比最后发酵效价降低了70 IU/mL;实验2发酵过程pH值偏低,全程为5.86～6.50,氨基氮代谢缓慢为40 mg/100 mL,最后林可霉素效价最低为4 480 IU/mL;实验3中废液在发酵进入48 h中后期的时候补入能促进菌丝体分泌,最后林可霉素为5 180 IU/mL,比对照发酵水平高出8.82%。可见实验3的实验设计有利于林可霉素菌利用吡唑酮废液生产林可霉素,为废物循环利用、变废为宝的可行性作了有意义尝试。     

Effects of the herbicide molinate on the metabolic activities of a degradative Streptomyces griseus strain

Abstract

Cometabolic degradation of the herbicide molinate was tested using two microorganisms, Arthrobacter sp., strain M3 and Streptomyces griseus strain M2; the latter classified on the basis of the presence of the enzymatic cofactor SF‐420. The strains M3 and M2, inoculated in a basic salts medium with glucose as carbon source and added with 100 mg L^‐1 of molinate, degraded respectively 35 and 51% of the herbicide in 36 days.

Increasing concentrations of molinate, ranging from 50 to 200 mg L^‐1 in glucose medium, did not affect the final ATP yield of the strain M2, but decreased the final growth yield and the ATP synthesis rate. Moreover, the onset of coenzyme SF‐420 synthesis was progressively delayed.

In contrast, surprisingly, SF‐420 final yield and production rate were increased by progressive increasing concentrations of molinate in the mineral medium.     

链霉菌碱性脂肪酶的研究

从杭州土壤中获得的一支链霉菌,通过ＵＶ、ＤＥＳ和Ｃｏ６０ － γ射线的５ 代诱变,选育成功了高产的Ｚ９４－ ２ 菌株,经过对Ｚ９４ －２ 的发酵研究,产碱性脂肪酶活力达５９６ ｕｍＬ,其最适培养基（λｕ Ｌ－１） 为：糊精１０、黄豆饼粉３０、尿素１０ 、Ｋ２ＨＰＯ４０ ．５、ＭｇＳＯ４·７Ｈ２Ｏ０ ．５、ＮａＣｌ１ 和ＡＥＯ９ ０．５ ,产酶的最适条件为：初始ｐＨ９．０～１０．０ ,２６℃培养４８ ｈ．对Ｚ９４－ ２ 与其他菌株的碱性脂肪酶的特性作了比较     

吸水链霉菌井冈变种JG5008转化系统的初建

吸水链霉菌井冈变种ＪＧ５００８的最佳转化条件是：ＪＧ５００８在添加ＭｇＣｌ２（ｃｆ＝０．００５ｍｏｌ／Ｌ）和甘氨酸（ρｆ＝０．５ｇ／Ｌ）的含１０％蔗糖的ＹＥＭＥ培养基中接种浓度ｎ≈１０＾８ｍＬ＾－１的ＪＧ５００８孢子悬液,３７℃摇床培养１２ｈ,收获菌丝体。在３２℃、溶菌酶浓度ρ＝２ｍｇ／ｍＬ的条件下溶菌１ｈ后制备原生质体,用Ｔ缓冲液在Ｒ２ＹＥ培养基上进行转化。本文初步建立了ＪＧ５００８的质粒载体系