S2Pills of paraformaldehyde (trioxymethylene) are commonly used in tapholes in sugar maple trees (Acer saccharum Marsh.) to increase the yield of sap collected for making syrup and sugar (2, 4, 5, 8). The explanation offered for this increase in sap yield is that microorganisms in the tapholes (7) cause premature decline and stoppage of the sap flow (1, 6), but that paraformaldehyde increases sap yield by inhibiting their growth (2). But what happens to the tree? To determine the effects of paraformaldehyde on the tissues surrounding tapholes, and on the microorganisms in those tissues, sugar maple trees were dissected and studied. This paper is a report on that study.S3.

For the effective utilization of microorganisms, either in biotechnology or agriculture, it is necessary to increase their original activity considerably. This can be performed by selection because even pure cultures of microorganisms are genetically heterogenous. The determination of the activity in a given strain is carried out in cultivation experiments. The error in the figures obtained decreases with repetition of the process. However, repetition of the determination raises the expenses. This can be compensated by reducing the number of strains included in the repeated experiments. This may involve a loss of profitable strains. The problem thus lies in choosing a selection procedure which minimizes labour and costs. In looking for the most suitable selection procedure mathematical methods may be used. However, in most cases it is difficult to get numerical results, even when assumptions are introduced for the sake of simplification. Computer simulation provides an alternative to solving some of the problems. For other problems it may be possible to find intuitive solutions which may not be the best ones, but are close to them.

With the discovery of various antibiotic resistant bacteria, evaluations of antimicrobial activities of natural compounds have been preceded on antibiotic susceptible and resistant microorganisms. Several types of natural compounds have been reported to have similar effects on target microorganisms as compared to the widely used antibiotics. Persicaria thunbergii (Polygonaceae) has been known to have anti-tumoral, anti-angiogenesis, anti-oxidation and anti-inflammation functions. In this study, aerial parts of P. thunbergii were extracted using methanol, chloroform, and ethyl acetate to identify possible anti-bacterial effects. Agar disk diffusion method and time-kill assay were done to evaluate the antibacterial effect of P. thunbergii extracts. Two extracts ethyl acetate (EAE), and chloroform (CFE) were tested against Staphylococcus aureus. As a result, the extract from CFE and EAE showed antibacterial effect against S. aureus. The extract EAE showed the strongest inhibition effect compared to CFE. These results demonstrate that the EAE extract which originated from P. thunbergii can probably play a role as an antibacterial agent.

Nitrate reducing microorganisms were isolated from soil and their denitrifying properties were compared under various environmental conditions. The isolated denitrifiers cultured in a liquid medium under anaerobic conditions responded differently to changing pH, temperature, nitrate or nitrite concentration. Unfavorable growth conditions led to the accumulation of nitrite. Various combinations of the selected bacteria revealed that interactions occur among the microbes during growth in relation to their denitrifying activity. Variation among bacterial species and specific environmental conditions resulted in different denitrifying characteristics; therefore, generalizations cannot be made regarding microbial denitrification in soil for possible applied uses.

Nineteen Duroc pigs which were obtained by hysterectomy were raised in five isolators to six weeks of age. Four of the five groups were inoculated with L. acidophilus and all groups were maintained on a 0.5% cholesterol milk formula diet. During this time serum cholesterol levels were 1000 mg. % ± 200. The bile acid composition of the feces collected at six weeks was principally hyocholic acid and chenodeoxycholic acid, which were the primary bile acids produced by the liver. Secondary bile acids formed from the primary acids by microbial dehydroxylation and oxidation were found only in trace amounts at 6 weeks. These small amounts of bacterial metabolites indicated minor microbial contamination which was confirmed by standard microbiological techniques. Small numbers of organisms other than Lactobacillus were found. No metabolism of hyocholic acid or hyodeoxycholic acids by these microorganisms could be detected in vitro at that time. At 6 weeks of age, 2 of the 5 groups were removed from the isolators and placed in a non-sterile environment. One of these groups continued to receive the milk formula and the other was weaned to a pig starter ration containing 0 .5% cholesterol. The other three groups remained in the isolators and received either the pig starter or the formula diet. When the two groups were taken from the isolators, they developed a complete microbial flora with Lactobacillus sp., Enterococcus, E. coli, slow lactose fermenters, and Staphylococcus predominating. At the same time the microflora increased in numbers and types in these groups, the serum cholesterol levels dropped dramatically to about 100 mg. % at 9 weeks of age. Also, the relative amounts of microbial metabolites of the bile acids, primarily hyodeoxycholic acid, increased in the feces and bile, and the metabolism of hyocholic acid in vitro by the fecal microorganisms was enhanced.

Abstract: Protein deficiency due to shortages of high-quality food protein is an urgent nutritional concern in many developing countries, and is part of a world food problem. Attempts to increase the production of edible food protein has resulted in development of new protein sources from oilseed meals, fishprotein concentrates, improved animal husbandry practices, new cereal varieties, leaf protein, microorganisms, and amino acid supplements. Improving the distribution and marketing of conventional protein foods has also been emphasized. Food habits and economic strategies are important considerations when new protein foods are introduced. Standardized laboratory analyses are necessary in evaluation of protein quality; biochemical techniques and methodologies are described. Toxicity, safety, processing and storage factors are presented in relation to protein quality and nutritional value of new protein products. The responsibility of scientists to deal with the challenge of protein malnutrition is discussed.

A survey was made to detect microorganisms useful for assaying butenolide [4-acetamido-4-hydroxy-2-butenoic acid gamma-lactone] and T-2 toxin [4beta, 15-diacetoxy-8alpha-(3-methylbutyryloxy)-12,13-epoxytricothec -9-en-3alpha-ol]. These mycotoxins produced by strains of Fusarium tricinctum have been implicated in mycotoxicosis of livestock. Although butenolide proved to be a very weak antibiotic, assay discs containing 100 mug of this toxin inhibited Sprillum serpens NRRL B-2052, Vibrio tyrogenus NRRL B-1033, and Xanthomonas campestris NRRL B-1459. T-2 toxin had no effect on 54 bacterial strains but inhibited 6 of 11 fungi. Growth of Rhodotorula rubra NRRL Y-7222 and Penicillium digitatum NRRL 1202 was retarded by assay discs containing 4 mug of T-2 toxin. Solutions with less than 1 mug of T-2 per ml toxin were readily detected by a pea seed germination test. Germination was reduced more than 50% when seeds imbibed solutions of 0.5 mug of T-2 toxin per ml. Butenolide had no effect on pea seed germination at concentrations as high as 200 mug/ml.

Foi analisado o produto dos três laticínios que fornecem leite a população piracicabana, sob a designação de pasteurizado tipo C. Procedeu-se a analise bacteriológica de coliformes, de anaeróbios esporulados, bem como a prova da redutase microbiana. As amostras de leite examinadas revelaram estado sanitário precário: as amostras 1 e 3 continham 1600 coliformes por 100 ml da amostra (N.M.P.) e a amostra 2, 350 por 100 ml. Quanto a presença da redutase microbiana a amostra 1 se classificou como ruim porque continha 20 milhões de células por ml, enquanto as amostras 2 e 3 como procedentes de leite bom, com 500 mil por ml, mas com a agravante de se apresentar peptonizada em 24 horas. | This paper describes the results obtained from bacteriological analysis of 3 milk samples. It has been assumed that all milk samples have a high contamination level; for this reason the milk that is distributed to the people may be boiled prior to use, in order to protect the human health. The author claimes that anaerobic microorganisms have a important role in bacteriological water analysis and related ones. Thus it is quite clear that there is a ratio between the amounts of this bacteria groups. One such method would achiaved best results in bacteriological analysis.