1964.-Quantitative spectrochemical analyses of inorganic elements in the vegetative cells of Escherichia coli, Sphaerotilus natans, Micrococcus roseus, Bacillus cereus, and the spores of B. cereus were made. The following elements were found to be present in the ash samples:

We have isolated and identified nine cultures of aerobic bacteria capable of growing on an elective medium containing uric acid as the only source of carbon, nitrogen, and energy. Four of these cultures were identified as Aerobacter aerogenes, two as Klebsiella pneumoniae, and the remainder as Serratia kiliensis, Pseudomonas aeruginosa, and Bacillus species. Another culture identified as P. fluorescens required both glucose and uric acid for growth. When 23 laboratory stock cultures were inoculated into the uric acid medium, A. aerogenes, B. subtilis, Mycobacterium phlei, P. aeruginosa, and S. marcescens were able to grow. These five cultures also grew when the uric acid was replaced with adenine, guanine, hypoxanthine, xanthine, or allantoin, but growth was poor. In all of these media, including the uric acid medium, addition of glucose along with the nitrogenous compounds yielded good growth. Induction experiments demonstrated that the ability of A. aerogenes, K. pneumoniae, P. aeruginosa, P. fluorescens, S. kiliensis, S. marcescens, B. subtilis, and Bacillus sp. to degrade uric acid is an induced property. Of these organisms, only Bacillus sp. accumulated a small amount of intracellular uric acid.

Press mud collected from sugar mills in Punjab, India were characterized and found to contain 75-80% organic matter, which mainly consists of cellulose, hemicellulose, lignin, protein, sugar, wax, etc. Biogas generation from press mud in a 2-litre batch reactor was studied at solid concentrations of 4 to 12%. Maximum yield of biogas was 0.24 L/g with 6% solids. Effect of Co ++ and Ni ++ concentrations on biogas yield was also studied. It was maximum at 5 µ moles/L of Co ++ and 6 µ moles/L of Ni ++ . The optimum C/N ratio for biogas generation was 18, which was higher than the normal C/N ratio of 14 in the press mud. Other substrates such as cow dung, bagasse and cane pith when mixed with press mud in different proportions have influenced biogas generation. Press mud when mixed with cow dung, biomethanation process became more stable. Particularly, cane pith when mixed with press mud in 1:1 ratio, the generation of biogas increased significantly. The methane content of the biogas was about 65%.

Endotoxin and hemolysin fromAeromonas hydrophila A(3) were studied to understand the pathogenicity of the organism. Neither the endotoxin nor the hemolysin alone produced typical red leg disease symptoms or death in frogs, even at a very high dosage of 8,000 μg; however, endotoxin and hemolysin together did. Further, histamine-stressed frogs died from hemolysin but not endotoxin. Hemolytic activity of hemolysin increased in cells that were preincubated with endotoxin. Results point to the conclusion that red leg disease in frogs represents a complex interaction between endotoxin and hemolysin and that stress-producing factors other than the endotoxin might trigger disease production.

Poultry litter (a mixture of rice hulls, sawdust and chicken excreta of broilers) mixed with the co-substrate cow dung and poultry droppings was evaluated under anaerobic conditions for the production of biogas (methane). Four laboratory scale reactors, R1, R2, R3 and R4, were set up with different proportions of waste poultry litter, cow dung and poultry droppings and had a 6% total solid concentration. Digestion was carried out for 50 days at room temperature, 32 ± 3 • C. Volatile solid degradation and specific gas production in the four reactors was 46%, 51.99%, 51.96%, 43% and 0.263, 0.469, 0.419, 0.221 l/g, respectively, based on the volatile solid (VS) feed. The methane yields were 71%, 72.5%, 72.6% and 70%, respectively. The COD reductions were 46.1%, 50.76%, 48.23% and 45.12%, respectively. A kinetic analysis showed that the anaerobic digestion of poultry litter with a co-substrate followed first order kinetics. Among the experimental reactors, R2 (25% cow dung, 75% poultry litter) gave the optimum results: a VS reduction of 51.99%, a specific gas yield of 0.469 l/g and a methane yield of 72.5%.