Cocci types

A second type of bacteria is the cocci (singular, coccus) which are spherical or ovoid in shape. The individual bacterial cells of this group may occur singly [Micrococcus), in chains (Streptococcus), in pairs [Diplococcus). in irregular bunches (Staphylococcus), and in the form of cubical packets (Sarcina). The coccus does not form spores and usually is nonmotUe. See Fig. 2. 

The estimation of a steady-state value of the CFF filtrate flux in general is difficult, because it is affected by many factors, including the type of membrane module, the characteristics of the membranes and suspensions, and the operating conditions. For example, it has been reported that the specific cake resistance of cocci in CFF was equal to the value obtained by dead-end filtration. However, the cake resistance became much larger in the CFF of bacillar microorganisms... 

Two types of organisms, Gram-positive cocci and Garm-negative rods predominate in the cellulose enrichment cultures. Assay of cellulase activity after four days of incubation indicates that by ultrasonic vibration of organisms attached to cellulosic fibers as much as seven times the amount of activity in the supernatant could be obtained (Table IX). 

The predominant NSLAB in Cheddar and Dutch-type cheeses are meso-philic Lactobacillus, which possess a cell wall-associated and intracellular proteinases. A range of intracellular peptidases, including dipeptidases, aminopeptidases, and endopeptidases, have been identified in Lactobacillus (see reviews by Khalid and Marth 1990a Peterson and Marshall, 1990). Interestingly, carboxypeptidase activity, which has not been found in lacto-cocci, has been reported in Lactobacillus casei (El Soda et al., 1978). 

The type of biosynthesis, exemplified by the levans and some dextrans, is generally associated with some Gram-positive organisms, usually cocci, and is the simplest type of saccharide synthesis to occur in bacteria. The enzymes involved are extracellular and do not require sugar nucleotide or lipid-phosphate sugars. 

Cell extracts of P. shermanii VKM-103 (wild type), P. shermanii KM-82 mutant (superproducer of vitamin B12), P. acnes CCM 322 and propionic add cocci P. coccoides) were tested as possible sources of antimutagens. The first two strains represented classical propionic acid bacteria, and P. acnes represented cutaneous propionibacteria. In the assay for antimutagenic activity S. typhimuhum TA 1535 his mutant) was used as the test organism (base pair substitution mutations tester). 

A spherical type of bacteria. Various species of cocci are responsible for human illnesses such as strep throat (streptococci), boils and similar infections (staphylococci), gonorrhea (gonococci), and meningitis (meningococci). Unsanitary practices of food handlers may result in the contamination of beverages and foods by these microorganisms. 

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