scholarly journals Characteristics of Curds With Milk Clotting Enzyme from Indonesian Local Isolate of Lactic Acid Bacteria

2020 ◽  
Vol 1 (2) ◽  
pp. 79-86
Author(s):  
Wendry Putranto ◽  
Apon Mustopa ◽  
Jendri Mamangkey ◽  
Netty Aritonang
Keyword(s):  
Enzyme Activity ◽  
Ammonium Sulfate ◽  
Observational Research ◽  
Ammonium Sulfate Precipitation ◽  
Fermentation Time ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Qualitative Observation ◽  
Milk Clotting Activity

To get the potential of lalcat acid bacteria isolate to produce Milk Clotting Enzyme (MCE), it is necessary to screen milk clotting activity both quantitatively and qualitatively. Through qualitative observation, the characteristics of the curd resulting from enzyme activity can be obtained. MCE is a protease that has the characteristics of milking. Based on the results of this observational research, the curd characteristic produced can be used as a benchmark to determine the length of time of fermentation and optimization of the determination of ammonium sulfate precipitation concentration. Isolate BAL shows the results of a compact curd at a fermentation time of 25 hours at 37 ℃ and the optimization results of the deposition of ammonium sulfate which shows the characteristics of a compact curd by 45% ammonium sulfate.

scholarly journals Study the influence of nitrogen on rennin production by fungi Rhizomucor miehei using solid-state fermentation

2016 ◽  
Vol 3 (5) ◽  
pp. 193
Author(s):  
Houthail Al-Ahmad Al-Jammas ◽  
Hassan Al-Fathi ◽  
Walid Al-Khalaf ◽  
Anton Taifor
Keyword(s):  
Enzyme Activity ◽  
Solid State ◽  
Protein Content ◽  
Yeast Extract ◽  
Wheat Bran ◽  
Solid State Fermentation ◽  
Rhizomucor Miehei ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Milk Clotting Activity

The effect of different nitrogen resources on the biosynthesis of milk clotting enzyme by Rhizmucor miehei was studied under solid state fermentation using wheat bran as base medium. Urea, peptone, albumin, casein, yeast extract were added with different concentrations (1%-10%). The response parameters were the ratio of milk clotting activity (MC) to proteolytic activity (PA) and protein content. The highest enzyme yield was achieved with casein at a rate of 2% w/w followed by 2% yeast extract, 1% albumin, 1% peptone, and 1% urea with values 5.6, 4.9, 4.2, 4, 3 mg/mL, respectively. Maximum enzyme activity (MCA/PA) was 50.4, 44.1, 37.8, 36, 27 SU for casein, yeast extract, albumin, peptone, and urea, respectively.

A novel milk-clotting enzyme from Aspergillus oryzae and A. luchuensis is an aspartic endopeptidase PepE presumed to be a vacuolar enzyme

2022 ◽  
Author(s):  
Yoko Takyu ◽  
Taro Asamura ◽  
Ayako Okamoto ◽  
Hiroshi Maeda ◽  
Michio Takeuchi ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Proteolytic Activities ◽  
Homologous Enzyme ◽  
Traditional Fermentation ◽  
Enzyme Source ◽  
Cheese Production ◽  
Milk Clotting Activity ◽  
Aspartic Endopeptidase

Abstract Aspergillus oryzae RIB40 has 11 aspartic endopeptidase genes. We searched for milk-clotting enzymes based on the homology of the deduced amino acid sequence with chymosins. As a result, we identified a milk-clotting enzyme in A. oryzae. We expected other Aspergillus species to have a homologous enzyme with milk-clotting activity, and we found the most homologous aspartic endopeptidase from A. luchuensis had milk-clotting activity. Surprisingly, two enzymes were considered as vacuole enzymes according to a study on A. niger proteases. The two enzymes from A. oryzae and A. luchuensis cleaved a peptide between the 105Phe-106Met bond in κ-casein, similar to chymosin. Although both enzymes showed proteolytic activity using casein as a substrate, the optimum pH values for milk-clotting and proteolytic activities were different. Furthermore, the substrate specificities were highly restricted. Therefore, we expected that the Japanese traditional fermentation agent, koji, could be used as an enzyme source for cheese production.

Measurement of milk clotting activity by rotational viscometry

2011 ◽  
Vol 78 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Mandy Jacob ◽  
Martin Schmidt ◽  
Doris Jaros ◽  
Harald Rohm
Keyword(s):  
Standard Method ◽  
Small Amplitude ◽  
Clotting Time ◽  
Milk Clotting ◽  
Rotational Viscometry ◽  
Milk Gelation ◽  
Reconstituted Milk ◽  
Flocculation Time ◽  
Milk Clotting Activity

Standard method for the determination of the activity of milk coagulants is the rotating bottle method, where clotting time is defined as the time when visually observable flocculation starts. Aim of this study was to verify whether it is possible to determine milk clotting time by rotational viscometry. Using three different coagulants and reconstituted milk of different pH and temperature, flocculation time and viscosity in steady shear was determined, and milk gelation was monitored by small amplitude oscillating shear rheometry. The results show that, independent of pH and temperature, milk clotting time is related to an apparent viscosity of 7·24±0·45 mPa.s, indicating that rotational viscometry can be used for the screening of flocculation time with an accuracy of approximately 6%.

scholarly journals Jacaratia corumbensis O. Kuntze a new vegetable source for milk-clotting enzymes

2009 ◽  
Vol 52 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Ana Rodrigues Duarte ◽  
Débora Maria Rodrigues Duarte ◽  
Keila Aparecida Moreira ◽  
Maria Taciana Holanda Cavalcanti ◽  
José Luiz de Lima-Filho ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ammonium Sulphate ◽  
Iodoacetic Acid ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Fractional Precipitation ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Milk Clotting Activity ◽  
Optimal Ph

The partial characterization and purification of milk clotting enzyme obtained from the (root latex) of Jacaratia corumbensis O. kuntze was studied, by fractional precipitation with ammonium sulphate and ion exchange chromatography. The ammonium sulphate precipitate showed five fractions (AS1- 0-20%; AS2 - 20-40%; AS3 - 40-60%; AS4 - 60-80%; AS5 - 80-100%) and among the fractions obtained, the 40-60% fraction (AS3) showed the highest milk clotting activity with a purification factor of 1.2 fold in relation to the crude extract. This fraction when applied on Mono Q column yielded two protein peaks (p1 and p2), but p1 pool showed the best milk-clotting activity. The optimal pH for the crude and partially purified extract was 6.5 and 7.0, respectively. The maximum milk-clotting activity was at 55ºC for the both crude and partially purified extracts. The enzyme was inhibited by iodoacetic acid which suggested that this enzyme was a cysteine protease, with molecular weight of 33 kDa.

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