The molecular genetics of C1 utilizing microorganisms an overview

The availability of recombinant DNA techniques has enabled the successful genetic analysis and manipulation of a range of C1 utilizing microorganisms. It has resulted in the identification of genes of interest on both plasmids and the chromosome; enabled the linkage of chromosomal genes to be determined; established the function and regulatory patterns of genes essential for utilization of C1 compounds and provided information on the evolution of methanogenic bacteria.     

The cutaneous microbiology of haired and hairless mice

H arnby , D., G owland , G., H olland , K.T. & K earney , J.N. 1990. The cutaneous microbiology of haired and hairless mice. Journal of Applied Bacteriology 69 , 686–691.
The cutaneous microflora of the mid-dorsal area of hairless and haired mice was studied by processing skin biopsies. In both C3H and CBA hairless genotype animals the prevalence of colonization and the bacterial density were significantly greater than in the haired animals. The dominant bacteria were staphylococci and aerobic coryneforms. No propionibacteria were isolated. Temporal studies with C3H mice showed that from 0 to 9 days after birth the cutaneous microflora reduced and from then on the haired genotype animals maintained a low cutaneous microflora, whilst hairless genotype animals gradually lost hair from head to tail and the microflora density increased. Reciprocal skin grafting between haired and hairless animals showed that the donor skin acquired the microflora characteristics of the recipient animal after 15 d post-grafting even though the donor skin remained morphologically true to genotype.     

Infants' exploration of scented toys: effects of prior experiences

To evaluate breastfed infants' responses to scented objects, we videotaped the facial and bodily reactions of sixty-three infants as they explored, in succession, three toys that were identical in appearance but different in their characteristic odor. Two of the toys were scented with odorants previously shown to be transmitted to human milk, one with ethanol and the other with vanilla, whereas the third toy was unscented. Each videotape was subjected to frame-by-frame analysis to measure a variety of behaviors that are considered either to be exploratory in nature in that they lead to perceptual information about the object or to reflect the infants' hedonic reaction. Analyses of these behaviors revealed that the infants looked more and vocalized less in the presence of the vanilla-scented toy and spent less time manipulating the ethanol-scented toy when compared with the unscented toy. Moreover, differential exposure to the odors of ethanol and vanilla, as indicated by differential consumption of alcohol by a parent or use of vanilla-scented product by the mother, was related to differential responses to these odors. These findings suggest that human infants are able to detect and retain information about the chemical features of their environment.      

Effect of ACTH on contralateral testicular damage and cytotoxic antisperm antibodies after unilateral testicular ischaemia in the rat

Unilateral testicular ischaemia in the rat results in morphological damage in the contralateral testis (sympathetic orchiopathia). An increase in serum cytotoxic antisperm antibodies and serum IgM levels seen in this condition when compared to controls was reduced by daily i.m. administration of a synthetic adrenocorticotrophic hormone (ACTH) for 7 days. ACTH would appear to be acting as an immunosuppressant, possibly reducing the effect of this autoimmune condition on subsequent fertility.     

Meat fermentations with immobilized lactic acid bacteria

Summary Two meat starter cultures, one ofLactobacillus plantarum and the otherPediococcus pentosaceus, were immobilized in calcium alginate beads and then lyophilized. Upon inoculation into meat, the immobilized cultures were found to ferment more rapidly than comparable free cell cultures.