Genetics of proteinases of lactic acid bacteria

Venema, Gerhardus

doi:10.1016/0300-9084(88)90084-3

Cited by 66 publications

(43 citation statements)

References 63 publications

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“…It was found that the extracellular fraction for all strains under study possessed the highest proteolytic activity as shown in Table 1. This is in agreement with Kok and Venema [20], who reported that the cell-wall-bound proteinases of lactic acid bacteria perform the first steps in the hydrolysis of casein. Seo et al [30], however, observed that the first step in casein degradation is mediated by proteases in the cell membrane.…”

Section: A Protease Activity Results Of Subcellular Fractionssupporting

confidence: 93%

Chemically Defined Medium for Optimization of Proteolytic Activity of Lactobacillus bulgaricus 761N

Nour¹,

Fattouh²,

El-Adawi³

2014

LSMR

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Abstract-Subcellular fractions of Lactobacillus bulgaricus 761N were investigated for their proteolytic activity that results in production of bioactive peptides in the cell-free supernatant. It was observed that the extracellular extract of L. bulgaricus 761N possessed the highest proteolytic activity of about 63.1 U/ml/min. Consequently, the extracellular fraction was chosen for assessing the proteolytic activity after each step of the optimization process was carried out. The factors of the optimization process involve the incubation period, temperature, pH, salinity (expressed by NaCl concentration), casein content, trace element concentration. The trace elements include cobalt chloride, copper sulphate, calcium chloride and ferrous sulphate. The basal medium used was skim milk agar. The other constituents of the chemically synthesized medium, that would optimize the proteolytic activity that in turn elevate the bioactive peptides production, are determined upon the results of the optimization process. The preferred conditions for maximal activity occurrence was after 48h incubation period, at pH 7, 37 o C, brackish environment at 5gl -1 NaCl content and 5gl -1 casein content. CaCl 2 and CoCl 2 were found to enhance the proteolytic activity at 1mM, while CuSO 4 and FeSO 4 were found to be needed in fewer amounts at 0.5mM and 0.1mM, respectively. The antibacterial activity of these bioactive peptides produced in the cell free supernatant was investigated against some human pathogenic bacteria. It was found that it impose a high antibacterial capacity on tested pathogens reaching 89% inhibition.

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Section: A Protease Activity Results Of Subcellular Fractionssupporting

confidence: 93%

Chemically Defined Medium for Optimization of Proteolytic Activity of Lactobacillus bulgaricus 761N

Nour¹,

Fattouh²,

El-Adawi³

2014

LSMR

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“…Thus, knowledge as to the types of proteinases that appear extracellularly during growth of lactococci -the substrate specificity and biochemical characteristics of the proteinases, and how the enzymes vary in different strains -is of importance in the use of lactococci in food production. Consequently, a proteinase(s) associated with the cell wall has been the subject of much research and the genetics of this proteinase have recently been well characterized (Haandrikman et al, 1989;Kok et al, 1988a, b;Kok & Venema, 1988;Vos et al, 19894, b).…”

Section: Introductionmentioning

confidence: 99%

“…It thus appears that the extracellular proteinase activity produced by L. lactis subsp. cremoris is due to basically one type of proteinase which may be present both in a cell-wall-associated and a free form, although small structural differences may exist in the proteinase obtained from different strains (Kok et al, 1988b, Kok & Venema, 1988; Vos et a!., 1989a).…”

mentioning

confidence: 99%

Purification and characterization of the free form of the lactococcal extracellular proteinase and its autoproteolytic cleavage products

Nissen‐Meyer¹,

Sletten²

1991

Journal of General Microbiology

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In addition to the cell wall proteinase, Lactococcus lactis subsp. cremoris produced significant amounts of a free extracellular proteinase. The free proteinase activity was highest in the late exponential and early stationary phase of growth, whereas the cell wall activity was highest in the last half of the exponential phase. Both proteinase forms had a pH optimum between 4-6 and 5.8, and they behaved similarly upon anion exchange and hydrophobic interaction chromatography, chromatofocusing and gel filtration, indicating that they were related. Purification to homogeneity, as judged by SDS-PAGE, resulted in a 50O00-80000-fold increase in the specific activity of the free proteinase. It contained two major protein species (termed pro150 and proll5) with proteinase activity. As judged by SDS-PAGE, the M, values of pro150 and pro115 were 150000 and 115000, respectively, and by chromatofocusing the isoelectric points were 4.3 and 4.1, respectively. Upon gel filtration, pro150 and pro115 had M, values of 300000 and 125000, respectively, indicating that pro150 was a dimer and pro115 a monomer. Pro115 was an autodegradation product of prol50. Other distinct autodegradation products had M, values of 90000 (p90), 53000 (p53), 37000 (p37) and 30000 (p30). These had little if any proteinase activity. Proll5, p90 and p53 had a common N-terminal sequence with that reported for the cell wall proteinase. Judging from its N-terminal sequence and M,, p30 was derived from the C-terminal half of p53. Cleavage of pro150 to pro115 generated p37.

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“…To achieve this rapid growth in the production of cheese and other fermented milk products, the proteolytic enzymes of lactococci are essential. Because of their economic importance, the proteinases of lactococci are the subjects of extensive biochemical and genetic research (4,14,25). The complete proteinase gene of Lactococcus lactis subsp.…”

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confidence: 99%

Identification of a gene required for maturation of an extracellular lactococcal serine proteinase

et al. 1989

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Directly upstream of the Lactococcus lachs subsp. cremoris Wg2 proteinase gene is an oppositely directed open reading frame (ORF1). The complete nucleotide sequence of ORF1, encoding a 33-kilodalton protein, was determined. A protein of approximately 32 kilodaltons was synthesized when ORFI was expressed in Escherichia coli by using a T7 RNA polymerase-specific promoter. L. lactis subsp. lactis MG1363 transformants carrying the proteinase gene but lacking, ORFl were phenotypicaHly proteinase deficient, unlike transformants carrying both the proteinase gene and ORF1. Synthesis and secretion of proteinase antigen by L. lactis could be detected with proteinase-directed monoclonal antibodies regardless of whether ORF1 was present. The requirement of ORF1 for proteinase activation was reflected in a reduction in the molecular weight of the secreted proteinase. Furthermore, deletion of the 130 C-terminal amino acids of the Wg2 proteinase prevented attachment of the enzyme to lactococcal cells.

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Genetics of proteinases of lactic acid bacteria

Cited by 66 publications

References 63 publications

Chemically Defined Medium for Optimization of Proteolytic Activity of Lactobacillus bulgaricus 761N

Chemically Defined Medium for Optimization of Proteolytic Activity of Lactobacillus bulgaricus 761N

Purification and characterization of the free form of the lactococcal extracellular proteinase and its autoproteolytic cleavage products

Identification of a gene required for maturation of an extracellular lactococcal serine proteinase

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