THE INACTIVATION OF BACILLUS SUBTILIS SPORES IN PENICILLIN BY GAMMA RADIATION

SUMMARY: Sodium benzylpenicillin, contaminated with Bacillus subtilis spores by freeze-drying a suspension of spores in an aqueous penicillin solution ( c . 50% w/v), was exposed to gamma radiation and a 70-tube dilution method was used to determine the surviving spores after various doses. The correlation coefficient between log₁₀ percentage survival and dose was −0.9523. The regression of the former on the latter was calculated and the decimal reduction dose found to be 20.2 × 10⁴ rads. The regression and the decimal reduction dose were similar to those obtained when suspensions of spores in distilled water were irradiated.     

枯草芽孢杆菌中性β—甘露聚糖酶的产生及性质

由土壤中分离出一株产中性β甘露聚糖酶的枯草芽孢杆菌（Ｂａｃｉｌｕｓｓｕｂｔｉｌｉｓ）,编号ＢＭ９６０２。该菌在液体培养条件下,产生中性β甘露聚糖酶。多糖能作为碳源,而单糖不能作为碳源;有机氮源优于无机氮源。产酶最适培养基组成：魔芋粉４％,牛肉蛋白胨和酵母膏各１％。产酶最适培养条件：培养基起始ｐＨ８５,３５℃,振荡培养３６ｈ。以槐豆胶为底物,培养滤液中性β甘露聚糖酶活力为９６ＩＵ／ｍＬ。酶在ｐＨ５０～１００和５０℃下稳定;作用最适条件为ｐＨ６０和５０℃;水解魔芋粉和槐豆胶均产生寡聚糖。     

'BULBIFORMIN', AN ANTIBIOTIC PRODUCED BY BACILLUS SUBTILIS

The antimicrobial spectrum of the antibiotic produced by Bacillus subtilis has indicated that it is chiefly antifungal. In the presence of the antibiotic, a characteristic bulb formation has been observed in the spores and hyphae of the test fungi. The active principle has been shown to be thermolabile. The importance of magnesium in relation to growth and antibiotic production has been indicated. Large quantities up to 30 p.p.m. are required for maximum production of the antibiotic which is not intracellular, but is secreted into the medium.
The data presented suggest that the antibiotic under consideration is different from those of B. subtilis previously described, therefore the name proposed for this antibiotic is 'bulbiformin'.     

枯草芽胞杆菌活菌制剂促进烧伤创面愈合的实验研究

目的　探讨枯草芽胞杆菌活菌制剂对烧伤创面愈合的影响。方法　通过大鼠深Ⅱ°烧伤模型,使用枯草芽胞杆菌活菌制剂,观察烧伤创面愈合过程中,成纤维细胞增殖周期的变化,以及测定羟脯氨酸（OHP）的含量,同时记录烧伤创面愈合时间,从而评价该制剂对烧伤创面愈合的影响。结果　应用枯草芽胞杆菌活菌制剂可促进成纤维细胞分裂、增殖,胶原含量提高,创面愈合时间明显缩短。结论　枯草芽胞杆菌活菌制剂具有促进烧伤创面愈合的作用。     

提高枯草杆菌(B.subtilis)原生质体再生率的研究(简报)

细菌原生质体制备和再生是研究细胞融合的前提条件,但关于其原生质体形成及再生的最适条件迄今尚缺乏系统的研究。再生率不高,且不稳定。本文研究了有关诸因素对供试菌株原生质体化及其活性的影响,尤其是提高再生率的措施。试验所用材料,菌株B.Subtilis Ki-2-132(Thr~-,Val~-,Ile~-,Str~+)由中国科学院遗传所赠送;溶菌酶由汉口蛋厂1981     

pNK289衍生质粒在牙孢杆菌中的分离稳定性

报道关于一系列pNK289衍生质粒分离稳定性研究结果。这些起源相同的质粒在Bacillus,subtilis AS1.1176中的分离稳定性存在差异,这种差异与质粒的大小和复制方式无关,而与质粒的考贝数有一定的关系。由于不稳定质粒pNK219在B.subtilis BD224宿主中能稳定遗传,所以推测宿主的遗传背景可能影响质粒的分离稳定性,这些研究不仅为进一步寻找与pNK289衍生质粒稳定性相关的基因奠定了基础,而且为在芽孢杆中构建稳定的重组质粒提供了理论依据。     

ULTRASTRUCTURE OF CHLORELLA PYRENOIDOSA AS AFFECTED BY ENVIRONMENTAL CHANGES

Chlorella pyrenoidosa (van Niel's strain) was cultured in four environmental conditions: light-glucose, light-galactose, dark-glucose, and dark-galactose. The gradual change in structure was observed when the cultures were transferred from light to darkness (dark adaptation). Cells grown in light contained well-developed chloroplasts and the normal cytoplasmic sub-units. During the transition to the complete heterotrophic mode of nutrition, the chloroplast regressed to the proplastid stage with a gradual reduction in thylakoid number. A prolamellar body was noted in the most regressed proplastid condition and plastid storage material was observed in all stages. The cell wall thickened during the transition. Cells adapted to darkness on galactose exhibited abundant cytoplasmic storage material with osmiophilic properties.     

AMELIORATION OF THE DELETERIOUS PLEIOTROPIC EFFECTS OF AN ADAPTIVE MUTATION IN BACILLUS SUBTILIS

The deleterious pleiotropic effects of an adaptive mutation may be ameliorated by one of two modes of evolution: (1) by replacement, in which an adaptive mutation with harmful pleiotropic effects is replaced by one that confers an equal benefit but at less cost; or (2) by compensatory evolution, in which natural selection favors modifiers at other loci that compensate for the deleterious effects of the mutant allele. In this study, we have measured the potential of these two modes of evolution to ameliorate the deleterious pleiotropic effects of resistance to the antibiotic rifampicin in the soil bacterium Bacillus subtilis. One approach was to measure the fitness cost of a series of spontaneous rifampicin-resistance mutations from each of several strains. The potential for amelioration by the replacement mode was estimated by the variation in fitness cost among the mutants of a single strain. Another approach was to introduce a series of different rifampicin-resistance alleles into a diversity of strains, and to measure the fitness cost of rifampicin resistance for each allele-by-strain combination. The potential for amelioration by the replacement mode was estimated by the variation in fitness costs among rifampicin-resistance alleles; the potential for compensatory evolution was estimated by variation in the fitness cost of rifampicin resistance among strains. This study has shown that the cost of rifampicin resistance may be ameliorated by both the compensatory and replacement modes.     

ANTIBIOTIC SUBSTANCES FROM A STRAIN OF BACILLUS SUBTILIS

SUMMARY: Strain B₇ of B. subtilis , isolated from soil collected from the gardens of the Bose Institute, Calcutta, was found to elaborate at least four different antibiotic substances. Fraction I was a brick red amorphous powder with certain resemblances to the bacillomycin group of antibiotics, soluble in alcohols, pyridine, etc., but insoluble in ether, water and acids. It had an ultraviolet absorption maximum at 276 mμ, melted with decomposition at 311°, and was a polypeptide positive to ninhydrin. On hydrolysis 12 amino acids were found. Fraction II was a white amorphous powder soluble in alcohols and ether but insoluble in water and petroleum ether. It melted at 158–162° and was a ninhydrin positive polypeptide composed of 7 amino acids. Fraction III was a yellow amorphous powder soluble in water and acetone, less soluble in ether and practically insoluble in chloroform. It was not a polypeptide. Fraction IV was a yellowish white amorphous powder with solubility characteristics similar to those of fractions I and II. It was a polypeptide composed of 10 amino acids.     

SULFUR AND THE TOXICITY OF THE RED ALGA CERAMIUM RUBRUM TO BACILLUS SUBTILIS1,2

Crystalline sulfur has been isolated from the red seaweed Ceramium rubrum and shown to be responsible for the toxicity of this alga to the growth of Bacillus subtilis. This alga was unusual in that it contained a much higher free sulfur content than other red and brown algae tested.     

AN AUTOMATED METHOD FOR QUANTIFYING THE L-ALANINE TRIGGER OF BACILLUS SUBTILIS SPORE GERMINATION AND COMPETITIVE INHIBITION BY D-ALANINE

We developed an automated method for studying the germination kinetics of Bacillus subtilis spores using a microtiter plate (MP) reader. Phosphate buffer supplemented with L-alanine was used to isolate the germination phase as determined by decrease in optical density (OD₆₃₀). Using a standard 96-well MP, L-alanine triggered germination kinetics were measured by automatic OD measurement every 3 min until the maximum OD₆₃₀ change (OD₆₃₀) was determined. When OD₆₃₀ values were plotted against L-alanine concentration on a double reciprocal plot, a straight line (R²= 0.98) was produced. The addition of D-alanine to the medium demonstrated classical competitive inhibition on double reciprocal plots. A 3-dimensional representation of the untransformed data showed the response surface nature of competitive inhibition. The method automates the tedious task of determining loss of refractility associated with spore germination under defined conditions so that inhibitors to germination can be studied. Since 96 OD₆₃₀ determinations can be done simultaneously in small volumes (200 μL) extensive data can be generated about inhibitors using relatively small spore crops in a single, short (1.4 h) incubation.