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J Youatt

Publications and source records attributed to J Youatt.

9 recordsLinked to original sources
PubMed1993

Calcium and microorganisms.

This review followed from experiments suggesting that some fungi do not require calcium. It was found that many studies of a calcium requirement in microorganisms had assumed specificity for chelation agents such as EGTA and A23187, which the reagents did not possess. Early studies still cited today often preceded the recognition that microorganisms required manganese and zinc. As a result of both of these misunderstandings, there was rarely any attempt to replace calcium by other important trace elements. In some studies that seem to have been overlooked, the apparent requirement for calcium depended on the growth conditions used. Escherichia coli, Neurospora crassa, and Saccharomyces cerevisiae were then selected for detailed consideration and it is concluded that further experiments are needed before the involvement of calcium is proved.

Bacteria↗
PubMed1985

DNA synthesis in relation to hyphal branching and wall composition in Allomyces macrogynus.

In A. macrogynus the first replication of DNA occurred after germination, at the time of the first branching of rhizoids. Before the second replication galactan in the wall exceeded the glucan content and was not firmly attached. After the second DNA replication hyphal lengthening commenced with an increase in the content of glucan but the walls lacked rigidity. At the time of the third replication walls underwent a change which commenced at the hyphal tip and worked back to the rhizoids, converting the hyphae to a rigid, cylindrical shape. Branching commenced after the fourth replication of DNA. Multiple branching occurred when mature plants were transferred to glucose-histidine-methionine solution without further DNA synthesis. Hyphal branching was used to show that A. macrogynus was able to use methionine, methionine sulfoxide, methionine sulfone, sodium sulfide, cysteine, cystathionine and homocysteine but not cystine. Thioacetamide supported growth through many subcultures showing that A. macrogynus can synthesize its sulfur amino acids.

Cell Wall↗
PubMed1976

The effect of actinomycin D on the formation of gametangia and mitosporangia in Allomyces.

The effect of actinomycin on gametangium and mitosporangium production in Allomyces arbuscula and A. macrogynus has been investigated. Male gametangium production was not more sensitive to actinomycin than female development. Actinomycin at 20 mug/ml added at the commencement of induction was completely inhibitory. The process became insensitive to actinomycin just before the first septum was laid down.

Chytridiomycota↗
PubMed1970

Possible inhibitory effect of teichoic acid on Bacillus subtilis transfer ribonucleic acid.

1. tRNA of Bacillus subtilis was found to be variably contaminated with membrane teichoic acid. 2. Samples with high contents of teichoic acid showed no accepting activity for tRNA(Phe) and tRNA(Tyr). 3. Removal of teichoic acid restored accepting activity and fractions containing teichoic acid, separated on Sephadex G-150, inhibited the charging of tRNA(Tyr). 4. The presence of teichoic acid did not inhibit the charging of tRNA(His).

Bacillus subtilis↗