Staphylococcus xylosus fermentation of pork fatty waste: raw material for biodiesel production

ABSTRACT The need for cleaner sources of energy has stirred research into utilising alternate fuel sources with favourable emission and sustainability such as biodiesel. However, there are technical constraints that hinder the widespread use of some of the low cost raw materials such as pork fatty wastes. Currently available technology permits the use of lipolytic microorganisms to sustainably produce energy from fat sources; and several microorganisms and their metabolites are being investigated as potential energy sources. Thus, the aim of this study was to characterise the process of Staphylococcus xylosus mediated fermentation of pork fatty waste. We also wanted to explore the possibility of fermentation effecting a modification in the lipid carbon chain to reduce its melting point and thereby act directly on one of the main technical barriers to obtaining biodiesel from this abundant source of lipids. Pork fatty waste was obtained from slaughterhouses in southern Brazil during evisceration of the carcasses and the kidney casing of slaughtered animals was used as feedstock. Fermentation was performed in BHI broth with different concentrations of fatty waste and for different time periods which enabled evaluation of the effect of fermentation time on the melting point of swine fat. The lowest melting point was observed around 46 °C, indicating that these chemical and biological reactions can occur under milder conditions, and that such pre-treatment may further facilitate production of biodiesel from fatty animal waste.

Halotolerant bacteria in the São Paulo Zoo composting process and their hydrolases and bioproducts

Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs). Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU) of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications.

The Effect of Temperature on Nitrate and Phosphate Uptake from Synthetic Wastewater by Selected Bacteria Species.

Aim: The aim of this study was to ascertain the effect of temperature on nutrient uptake ability of four bacterial species. Methodology: A total of four bacterial species (Klebsiella sp., Pseudomonas sp., Lysinibacillus sp. and Staphylococcus sp.) were used for the study. The media used for the investigation was synthetic wastewater. Four different temperatures (25ºC, 30ºC, 35ºC and 40ºC) were used for the investigation. The study was carried out under shake flasks conditions. Immediate after inoculation with the respective test bacterial species and every 24 h for a 96 h incubation time, aliquot wastewater samples were removed from the flasks for the estimation of total phosphate, nitrate, pH and growth rate, using standard procedures. Results: The results revealed phosphate and nitrate removal ranges of 10.84 % to 55.55 % and 90.67 % to 97.27 %, respectively in the presence of the Klebsiella sp. In the presence of the Pseudomonas sp, Lysinibacillus sp. and Staphylococcus sp., phosphate removals ranges of 0.36 % to 46.98 %, 11.89 % to 50.80 % and 2.74 % to 51.21 % were observed, respectively. For nitrate concentrations, removal levels that ranged from 2.19 % to 92.95 %, 0.97 % to 23.12 % and 7.56 % to 91.66 % were observed in the presence of Pseudomonas sp, Lysinibacillu ssp. and Staphylococcus sp., respectively. All the test bacterial species showed some measure of efficiency in phosphate removal. For nitrate removal, the Lysinibacillus sp. did not exhibit remarkable nitrate removal ability at any of the temperatures. In addition, the optimum temperatures for phosphate removals were observed to be 30ºC to 40ºC for the Klebsiella sp. and Pseudomonas sp; and 30ºC to 35ºC for the Lysinibacillus sp. and Staphylococcus sp. For nitrate removal, optimum temperatures for removal were observed to be 25ºC to 40ºC, for the Klebsiella sp and 25ºC to 35ºC, for the Pseudomonas sp. and Staphylococcus sp. Conclusion: The study was able to reveal the optimum temperatures for phosphate and nitrate uptake in synthetic wastewater by the test bacterial species.

Isolation and identification of poly beta hydroxybutyric acid accumulating bacteria of Staphylococcal sp. and characterization of biodegradable polyester.

Staphylococcus sp. strain BP/SU1, capable of degrading the biopolymer and utilize it as a source of carbon and energy, was isolated from activated sludge using METABOLIX (MBX D411G). It was found that this strain was capable of accumulating poly(3-hydroxybutyric acid) P(3-HB), as granule poly (3-hydroxybutyric acid), p(3-HB), inclusion bodies when grown under suitable nutrient conditions. These strains could sustain cell growth up to a dry mass of 9.24 g/l with a doubling time of 8 to 10 hr and could accumulate P(3-HB) as granular inclusion bodies to a cell dry weight of more than 12%. P(3-HB) accumulated by this organism was isolated and characterized through NMR, FT-IR spectroscopy, UV Spectroscopy, Mass spectroscopy and Differential Scanning Calorimetry. P(3-HB) granules so isolated showed physical and chemical properties that should be possessed by a superior quality thermoplastic biopolymer.

Growth and Siderophore Production of Staphylococci in Human Peritoneal Dialysate

Although activity of iron uptake system (IUS) was thought to play an important role in staphylococcal growth in human peritoneal dialysate (HPD) solution, siderophore production, one of the well-known IUS, was not yet detected directly in HPD solution. Therefore, we tried to detect siderophore production directly in HPD solution by using a newly developed chrome azurol S (CAS) agar diffusion assay and to investigate the effect of IUS activity on bacterial growth in HPD solution. According to the susceptibility test for streptonigrin and the productivity of siderophore in the iron-deficient (ID) medium, Staphylococcus aureus ATCC 6538 strain and Staphylococcus epidermidis clinical isolate had higher IUS activity and grew better than S. aureus ATCC 25923 strain in the ID medium. These bacteria did not grow and produce siderophore in the unused chronic ambulatory peritoneal dialysis solution. However, these bacteria grew and produced siderophore in the HPD solution. Moreover, S. aureus ATCC 25923 strain with lower activity of IUS grew poorly and produced smaller amount of siderophore in HPD compared to S. aureus ATCC 6538 strain and S. epidermidis clinical isolate with higher activity of IUS like in the ID medium. To the best of our knowledge, this is the first report that sidero-phore production is directly detected in the HPD by CAS agar diffusion assay. These results indicated that activity of IUS plays an important role in bacterial growth in the HPD solution and pathogenesis of continuous ambulatory peritoneal dialysis peritonitis.

Estudio clínico comparativo de la evolución del cordón umbilical utilizando dos tipos de antisépticos: gerdex/alcohol / Comparative clinic study of the evolution of the umbilical coord utilizing two types of antiseptics: alcohol/gerdex

Se realizó un estudio clínico comparativo en noventa recién nacidos del Hospital Materno Infantil "Joel Valencia Parpacén" de Caracas, del cordón umbilical utilizando dos tipos de antisépticos gerdex al 10 por ciento y alcohol al 70 por ciento. De todas las variables analizadas resaltó de importancia el tiempo de caída del cordón umbilical, siendo significativo el promedio menor de días en los recién nacidos a quienes se les aplicó Gerdex al 10 por ciento, observándose además que al utilizar este antiséptico, el color amarillo sin halo eritematoso alrededor del cordón umbilical predominó en relación con el color oscuro y anillo eritematoso presente con el uso de alcohol al 70 por ciento. Estéticamente la evolución del cordón umbilical fue mejor con Gerdex al 10 por ciento

Effect of various microbial preparations on P-388 mouse lymphocytic leukemia

Four bacteria-derived immunopotentiators were tested for their protective effect on a P-388 mouse lymphocytic leukemia model. The microbial test products were prepared from the following bacterial strains: ATCC 35983 Staphylococcus epidermidis isolated from a patient with IV catheter; ATCC 31874, a patented strain listed as Staphylococcus epidermidis isolated from the urine of a cancer patient; ATCC 25615 Staphylococcus hominis obtained from a child with lymphocytic leukemia, and ATCC 25614 Staphylococcus warneri, an isolate from a patient with adenocarcinoma of the breast. A limited degree of protection and prolongation in survival time was observed in the animal group treated with the bacterial strain ATCC 31874