STARCH IN FUNGI. II. INDUCTION OF AMYLOIDITY IN MEMBERS OF DIVERSE GENERA

Nonamyloid hyphae from fungal fruit bodies which normally produce amyloid structures can be induced to produce starch molecules when incubated in glucose-1-phosphate solution. Hyphae from fruit bodies without natural amyloid structures could not be induced to produce starch. The genes for the starch-synthesizing enzymes are apparently activated when fruit body formation is initiated.     

STUDIES OF LINKAGE IN POPULATIONS. XIV. HISTORICAL CHANGES IN FREQUENCIES OF GENE ARRANGEMENTS AND ARRANGEMENT COMBINATIONS IN NATURAL POPULATIONS OF DROSOPHILA ROBUSTA

Abstract Data are reported showing large directional changes in the frequencies of some gene arrangements and arrangement combinations in certain natural populations of Drosophila robusta in the eastern United States. The changes involve the same X‐chromosomal inversion differences in two of the three localities studied and similar autosomal inversions in all three. These genetic changes provide a rare opportunity to observe evolutionary forces at work in nature. They are interpreted as being due to natural selection.     

THE ROLE OF ENDOMYCORRHIZAE IN REVEGETATION PRACTICES IN THE SEMI-ARID WEST. I. A COMPARISON OF INCIDENCE OF MYCORRHIZAE IN SEVERELY DISTURBED VS. NATURAL ENVIRONMENTS

A comparison of a natural, undisturbed ecosystem, a mid-elevation sage community, with a severely disturbed old roadbed through this community revealed that more than 99% of the plant cover in the natural community was mycorrhizal (vesicular-arbuscular), whereas less than 1% of the plant cover in the disturbed area (roadbed) was mycorrhizal. Examples of nonmycorrhizal plants as primary successional species in severely disturbed habitats are discussed. The importance of maintaining or re-establishing the mycorrhizal fungal component in reclamation programs designed to produce stable ecosystems is emphasized.     

THE PRODUCTION OF ANTIBIOTICS IN SOIL V. BREAKDOWN OF GRISEOFULVIN IN SOIL

When griseofulvin (I; R = Cl, R '= OCH₃), a chlorine-containing antibiotic produced by Penicillium nigricans , was added to fresh garden loam, after an initial lag it disappeared rapidly. When further griseofulvin was added it was inactivated from the start and at rates which increased with each successive addition, suggesting that it was degraded biologically. The numbers of one organism, a Pseudomonas sp., increased in the soil steadily after adding griseofulvin.
When a little soil was added to a solution (pH 7·0) containing inorganic salts and griseofulvin as the sole carbon source, bioassays showed that the griseofulvin disappeared within 5 days. An organism isolated from the broth was identified as the Pseudomonas sp. thought to break down griseofulvin in soil. Griseofulvin also disappeared from a broth at pH 5·0 inoculated with soil, but at this lower pH value a dematiaceous fungus was responsible for its breakdown.
The Pseudomonas sp. also degraded two derivatives of griseofulvin, dechlorogriseofulvin (I; R = H, R'= OCH₃) and the amine (I; R = Cl, R '= NH₂). Cl^– was detected in the solutions after breakdown of griseofulvin by the Pseudomonas ; the amount present agreed well with that calculated on the assumption that all the chlorine in the griseofulvin supplied was liberated as Cl^–. Spectrophotometric examination of the solutions showed no metabolites with the aromatic ring intact, and confirmed the complete breakdown of griseofulvin suggested by the liberation of Cl-.     

钩虾体内寄生棘头虫幼虫在中国的首次报道

钩虾(Gammarus sp.)是一类栖息于水底及聚集于水草丛的端足类动物.我国对钩虾的研究主要是种类鉴定,而且也主要是近几年的研究成果1.钩虾作为棘头虫的中间宿主,在国外已有很多报道2,3.然而在国内对棘头虫生活史的研究甚少,特别是对鱼类的棘头虫4.       

SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H⁺) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen''s α-glucosidase (maltase), was found.     

ENDOPHYTE-HOST ASSOCIATIONS IN GRASSES. XVI. PATTERNS OF ENDOPHYTE DISTRIBUTION IN SPECIES OF THE TRIBE AGROSTIDEAE

Distribution of Acremonium endophytes in several species of Agrostideae is determined through surveys conducted in the field and in grass herbaria. Widespread geographic distribution of Acremonium in a particular grass species may indicate early colonization of the grass as a host, while a narrow pattern of geographic distribution suggests more recent colonization of the grass. Two grasses that appear to show a narrow endophyte distribution include Agrostis alba and Ammophila breviligulata. Cultural features of endophytes from several grasses are compared. A new variety of Acremonium typhinum is proposed to accommodate the endophyte from A. breviligulata. An endophyte in Agrostis alba is identified as Acremonium starrii. It is also suggested that Acremonium endophytes are spreading in grasses and may be progressively colonizing new hosts.     

中国枝孢属研究XXVII.

本文报道枝孢属Cladosporium Link: Fries 的二个新种: 柚木生枝孢C. tectonicola 和莴苣生枝孢C. lactucicola。模式标本收藏于云南农业大学真菌标本室(MHYAU)。     

SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. III

1. The relationship of sucrose and water concentration to invertase activity in vivo and in vitro has been studied under the same environmental conditions. 2. The sucroclastic activity of S. cerevisiae cells and of invertase solutions prepared from them reacts to changes in sucrose and water concentration in an identical manner. 3. The invertase contained in living yeast cells is just as freely exposed to the conditions of sucrose and water concentrations of the suspending medium as it would be if it were contained in a cell-free solution. Weight is added to the previous suggestion (2) that yeast invertase exerts its physiological activity in a region quite close to the surface of the cell.     

ENERGY OF MAINTENANCE IN ESCHERICHIA COLI.

McGrew, Sarah B. (Pennsylvania State University, University Park) and M. F. Mallette. Energy of maintenance in Escherichia coli. J. Bacteriol. 83:844-850. 1962.-Relatively dense populations of Escherichia coli B in log phase were used to detect utilization of exogenous glucose for maintenance without growth. Turbidity at 400 mmu was used as the measure of growth, since it should reflect changes in either cell number or size. A threshold level of glucose was observed below which turbidity did not change during short-time experiments. Repeated additions of glucose during prolonged incubation at 37 C either increased the turbidity slowly or maintained it, depending on the amount of glucose. Plate counts to follow viability showed slow decreases for 10 days, while the unfed controls lost viability quite rapidly. From these results it was concluded that E. coli specifically utilized exogenous glucose for maintenance, without growth. The conflict of this opinion with that of earlier workers is discussed and some implications suggested.     

中国枝孢属研究XXVII.*

本文报道枝孢属Cladosporium Link: Fries 的二个新种: 柚木生枝孢C. tectonicola 和莴苣生枝孢C. lactucicola。模式标本收藏于云南农业大学真菌标本室(MHYAU)。     

中国柱隔孢属分类研究Ⅴ.

本文报道柱隔孢属一新种:紫穗槐柱隔孢Ramularia amorphae Wang et Zhang sp.nov.和两个新记录种:碧冬茄柱隔孢R.petuntae Cooke,菜豆柱隔孢R.phaseoli(Drummond)Deighton。新种提供了拉丁文描述。每个种均有汉文描述并附图。研究的标本收藏于云南农业大学真菌标本室。     

云南猪屎豆属6种植物的核型初报

本文对猪屎豆属(Crotalaria)6种植物的核型进行了研究(C. yunnanensis仅报道了染色体数目),并结合它们的分类和分布特征,初步探讨了它们的演化关系;其中C. bracteata的染色体数目和核型以及C. yunnanensis的染色体数目均为首次报道。     

THE OCCURRENCE OF PORPHYRINS IN CULTURES OF C. DIPHTHERIAE

A complex porphyrin which has not been hitherto described is found in liquid cultures of C. diphtheriae. The porphyrin is a combination of coproporphyrin with both iron and copper, and shows an oxidation-reduction change. This is the first report, as far as we are able to determine, of a porphyrin compound which contains both iron and copper in its molecule. Its source is in all probability the cytochome of the bacilli. The content of porphyrin is proportional to the biological titer of the culture filtrate; the suggestion is offered that the toxin itself is derived from cytochrome.