Azospirillum brasilense Sp7 and its ntrA (rpoN), ntrBC, and ntrC mutants have been evaluated for their capabilities of poly-3-hydroxybutyrate (PHB) accumulation in media with high and low ammonia concentrations. It was observed that the ntrBC and ntrC mutants can produce PHB in both low- and high-C/N-ratio media, while no significant PHB production was observed for the wild type or the ntrA mut...

Bacterial cultures of bacillus species capable of producing bacitracin were isolated from local habitats (garden soil, timber yard soil and sea water) and screened for the production of bacitracin on nutrient media against test organisms viz: Micrococcus luteus,(ATCC 9341) & Staphylococcus aureus (ATCC 13565).Optimization of culture conditions and media composition for bacitracin production was...

Lactobacillus brevis ATCC 14869 exhibited a carbon catabolite de-repressed (CCR) phenotype which has ability to consume fermentable sugar simultaneously with glucose. To evaluate this unusual phenotype under harsh conditions during fermentation, the effect of lactic acid and hydrogen ion concentrations on L. brevis ATCC 14869 were examined. Kinetic equations describing the relationship between ...

Growth of four Trichoderma strains were tested on lignocellulosic by-products in solid state fermentation (SSF). The strains were also analyzed for their survival rate and growth after lyophilization on these carriers. All applied monocomponent and bicomponent media were substrates for the production and preservation of Trichoderma biomass. However, the maximum number of colony forming units (C...

This paper presents a study of low-ultrasonic energy that can be affected to increase yeast growth. Forces of the ultrasonic stimulation in the yeast media broth, a liquid nutrient medium for the culture of yeast, produce change of liquid densities and surrounding pressure, which affect to the yeast growth. A utilized ultrasonic system including transducer of 20 kHz was varied powers and applie...

Whilst the breakdown of glucose to D-3-phospho-. glyceric acid (PGA) has been observed in a number of micro-organisms (Werkman, Zoellner, Gilman & Reynolds, 1936; Stone & Werkman, 1936a, b, 1937; Wood, Stone & Werlmaan, 1937; Still, 1940), the formation ofPGA from pentoses has so far only been observed in the case of Propionibacterium pentosaceum (Barker & Lipmann, 1949). The present investigat...

Microorganisms dead or alive are successfully exploited for bioremediation of xenobiotics by biosorption. Textile effluents are among the most difficult-to-treat wastewaters, due to their considerable amount of recalcitrant and toxic substances. Fungal biosorption is viewed as a valuable additional treatment for removing pollutants from textile wastewaters. The overall economics of the biosorpt...

Fermentation of whey by Clostridium acetobutylicum yielded butanol and acetone in a ratio of approximately 100:1. This ratio amounted to only 2:1 in synthetic media with glucose, lactose, or glucose plus galactose as substrates. Removal of citrate from whey and addition of minerals resulted in an increase in the amount of acetone produced. Experiments carried out in a chemostat with a low-phosp...

Twenty-five isolates of nutritionally variant streptococci submitted to the Streptococcus Laboratory of the Center for Disease Control over a 2-year period were tested for growth requirements and for biochemical reactions. After they were recovered from storage in blood at -170 degrees C, all isolates grew within 48 h in both thioglycollate broth and Todd-Hewitt broth supplemented with 0.001% p...

Authors M.E. Pintado, A.I.E. Pintado, and F.X. Malcata are affiliated with Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, P-4200 Porto, Portugal. Address inquiries to Dr. F.X. Malcata. ABSTRACT The rates were monitored on biomass increase, polysaccharide production and viscosity development of whey broth and a control synthetic broth d...