Characteristics of proteinases and lipases produced by seven Bacillus sp. isolated from milk powder production lines

Chen, L.; Coolbear, Tim; Daniel, Roy M.

doi:10.1016/j.idairyj.2003.10.006

Cited by 70 publications

(48 citation statements)

References 46 publications

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“…Reaction with d-valyl-l-leucyl-l-lysine p-nitroanilide dihydrochloride Chen et al (2004) Reaction with azo-casein Immunomethods Enzyme-linked immuno-sorbent assay (ELISA) Chen et al (2003) Agar plate methods Agar-well diffusion assay Braun et al (1999) …”

Section: Comparison Of Cultivation Plate Methods For Proteolytic Micrmentioning

confidence: 99%

“…Thus, there is only a weak correlation between counts of aerobic sporeformers and risk of spoilage (Chen et al 2004). Most extracellular proteinases are synthesised at the end of exponential phase and during stationary phase and sporulation.…”

mentioning

confidence: 99%

“…Proteolytic changes manifest themselves by increase in non-protein nitrogen concentration and by para-κ-casein formation accompanied by casein micelles destabilisation and milk coagulation (Chen et al 2003). Bacillary proteinases usually have a pH optimum in alkaline zone (Chen et al 2004) and a temperature optimum at 30-37°C (Braun et al 1999).…”

mentioning

confidence: 99%

“…Although low water activity inhibits microbial growth, enzymatic activity persists and causes sensory and functional defects (Chen et al 2004). Lowered thermo-stability and increased foam-formation of reconstituted milk can appear in consequence of density 10 6 -10 7 CFU/ml of psychrotrophs in raw milk (Sørhang & Stepaniak 1997).…”

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confidence: 99%

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Problems with detection of proteolytic microorganisms and their undesirable activities in milk

Němečková¹,

Pechacova²,

Roubal³

2009

Czech J. Food Sci.

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Abstract:Occurrence of proteolytic enzymes in milk is often associated with technological problems and sensory, rheological and functional defects of final dairy products. Thus, the simple, cost-effective and available laboratory method for evaluation of undesirable proteolysis risk is needed. In our work we have tested cultivation plate methods and chemical methods (formol titration, ammonium reflectometric determination, the Kjeldahl method, the agarwell diffusion assay and spectrofotometry after cleavage of azo-casein) to choose the proper ones which can provide information on undesirable proteolytic changes especially in raw milk. Although the microbiological analyses cannot detect enzymes indigenous to milk, but only the quantity of producers of microbial enzymes, they seem to be the most acceptable, particularly usage of the Glucose-Trypton-Yeast Extract agar with 10% vol. of sterile milk added before pouring onto plates (incubation at 30°C for 72 h). The chemical methods are not sensitive enough to analyse the real milk samples.

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Section: Comparison Of Cultivation Plate Methods For Proteolytic Micrmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Problems with detection of proteolytic microorganisms and their undesirable activities in milk

Němečková¹,

Pechacova²,

Roubal³

2009

Czech J. Food Sci.

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“…cereus geralmente sintetiza uma variedade de enzimas, entre elas, as proteases e lipases. Estas enzimas são responsáveis pelo desenvolvimento de atributos sensoriais indesejáveis em produtos lácteos (ALMEIDA et al, 2000;CHEN et al, 2004).…”

Section: Introductionunclassified

Incidence and lipolytic and proteolytic activity of Bacillus cereus in UHT milk

Maziero¹,

Viana²,

Neto³

et al. 2015

Pubvet

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ResumoBacillus cereus é um microrganismo termodúrico que pode apresentar atividade lipolítica e proteolítica, comprometendo a qualidade de produtos lácteos. Sua presença foi avaliada em 110 amostras de 19 marcas comerciais através de duas metodologias, uma qualitativa e outra quantitativa. Pela técnica quantitativa nenhuma amostra apresentou contagens acima do limite de detecção do método (>10 UFC/ml). Já pelo método qualitativo 18 amostras Londrina, V. 5, N. 27, Ed. 174, Art. 1174, 2011 incubação, no entanto, prolongando esta incubação para 96h, dez cepas formaram halos característicos de lipólise. Foi constatado que 44,4% das cepas de B. cereus apresentaram atividade lipolítica e proteolítica simultaneamente.. et al. Incidência e avaliação da atividade lipolítica e proteolítica de Bacillus cereus em leite UHT. PUBVET,A presença de B. cereus proteolítico e lipolítico em leite UHT pode causar defeitos sensoriais durante seu prazo de validade.Palavras-chave: lipólise, proteólise, geleificação. Incidence and lipolytic and proteolytic activity of Bacillus cereus in UHT milk AbstractBacillus cereus is a thermoduric microorganism that may has lipolytic and proteolytic activity, decreasing the quality of dairy products by causing sensorial defects during shelf life. The presence of B. cereus was evaluated in 110 UHT milk samples from 19 commercial brands, using two methods:

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