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Biomedical subjects

L A Mazza

Publications and source records attributed to L A Mazza.

15 recordsLinked to original sources
PubMed1983

[Production of glucose isomerase by Streptomyces phaeochromogenes].

The production of glucose isomerase was studied in the Streptomyces phaeochromogenes NRRL B-3559 strain. The influence of the medium composition and the aeration conditions was determined Selection of colonies was necessary to obtain the best results. A grey colony proved to be the most productive one. It was necessary to use the frozen inocula in order to obtain steady reproduction values. It was possible to achieve the maximum enzymatic level (1600 UE/1 min) using a CoCl2. 6H2O concentration of 0.18 g/l. The aeration studies conducted in a mechanically stirred fermentor showed results comparable to those obtained in shaker flasks, operating at 550 rpm and using an air flow of 1 1/1 min. The culture proved to properly aerated since both the cellular oxygen uptake and oxygen demand were similar (Table 1).

Aerobiosis↗
PubMedDate not supplied

[Influence of the sterilization technic and culture media components on the growth and dissociation of Brucella abortus strain 19 in submerged cultures].

Submerged cultures of Brucella abortus strain 19 were studied in shaking flasks. The influence of the sterilization methods and the medium composition on the bacterial yield and cellular dissociation were studied. The selected medium was as follows (amounts in g/l): casein pancreatic hydrolizated 30; yeast extract 10; glucose, 30; sodium phosphate dibasic anhydrous 3,3; sodium monobasic monohydrate 9. Cell concentration of 8 . 10(10) viable cell/ml was obtained after 48 hours when the medium components were separated and sterilized at 121 degrees C for 20 min in autoclave.

Bacteriological Techniques↗
PubMedDate not supplied

[Production of soy bean inoculants. Behavior of supports based on peat from Tierra del Fuego sterilized by vapor and ethylene oxide].

The survival of Rhizobium japonicum was studied in neutralized and sterilized peats from Ushuaia and Rio Grande. The carriers were sterilized by ethylene oxide and by autoclaving. Similar counts for Rhizobium (5 x 10(8) cel/g) were obtained in peat-cultures sterilized by both methods, after eight months. A good nodulation and nitrogen fixation capacity was observed with inoculated soybean plants. Using the strain Rhizobium japonicum E-45, no appreciable difference in symbiotic effectiveness was found between the inoculants prepared with the two peats.

Argentina↗
PubMedDate not supplied

[Production of inoculates for leguminous plants. Production of cellular suspensions of Rhizobium (Lotus group)].

The influence of culture medium composition and operative conditions on the cellular growth of Rhizobium sp (group Lotus) strain is studied. As much as 1 x 10(9) cell/ml were obtained in 16 hours using sucrose in the medium as carbon source. The best growth rate was obtained (mu = O,22 h-1) when the experiments were performed at 400 r.p.m. and one volume of air/volume of medium x minute (OAR = 793,0 ml of oxygen/1 h).

Cells, Cultured↗
PubMedDate not supplied

[Production on alkaline protease by Bacillus subtilis NRRL 3411].

The aim of this work was to study the influence of medium composition and the effect of the operative conditions on alkaline protease production. Several nitrogen sources (in amount of 10 g/l) were tested and compared with bacto peptone Difco: Casein was the best. The addition of "Tween 80" 0,5% resulted in a marked increase in yields of the alkaline protease. The maximum alkaline protease production (3.342.290 UAPAM/g) was achieved using the following medium: Lactose 20 g/l; casein 10 g/l; NaCl 1,5 g/l; MgSO4.7H2O 0,15 g/l; CaCl2.2H2O 0,06 g/l; MnCl2.4H2O 0,01 g/l; "Tween 80" 5,0 g/l; EDTA 1,5 X 10(-4)M; KH2PO4 1,5 g/l; K2H PO4 1,5 g/l; Na2SO4 1,5 g/l. It was found that a volumetric relation of 0,1 ml, vol. of medium/vol. of flask at 25 degrees C of temperature was the best process condition.

Bacillus subtilis↗
PubMedDate not supplied

[Alkaline protease production].

The influence of culture medium composition on alkaline protease production was studies. Various carbon sources such as glycerol, glucose, lactose and starch were tested. Different concentrations of lactose and bactopeptone have been tested. The optimum medium composition was found to be: (g/l) lactose 20.0; bactopeptne Difco 10.0; NaCl 1.5;mgSO47.H20 0.15; CaCl2 0.06; K2HPO4 1.5; KH2PO4 1.5; Na2SO4 1.5; MnCL2.4H2O 0.01. A cell concentration of c.a 9.5 g/l has been obtained after 30 hours. The maximun alkaline protease production (5,000 uAPAM/ml) was attained after 60 hours. The trials were carried on rotary shaker in 1 liter erlenmeyer flasks containing 250 ml of medium.

Bacillus subtilis↗
PubMedDate not supplied

[Production of alkaline protease from acid cheese whey].

The use of acid cheese whey as an essential substrate for the production of alkaline protease was studied by growing Bacillus subtilis NRRL 3411 on different conditions of aereation. The maximum enzymatic activity of 17 000 proteolytic units was obtained in the following conditions: 200 RPM, air flow of 1 v/v minutes (KLa 37 h-1), separate sterilization of the medium components and periodical additions of peptone.

Animals↗