Novel milk-clotting enzyme from Bacillus stearothermophilus as a coagulant in UF-white soft cheese

Ahmed, Samia A.; Wehaidy, Hala R.; Ibrahim, Osama O; Ghani, Salem Abd El; El-Hofi, Mahmoud

doi:10.1016/j.bcab.2016.06.011

Cited by 69 publications

(31 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Over the centuries, microbial proteases have played a major role in the production of traditional fermented foods, and now the industrial enzyme sector, provides the world with biocatalysts for use in many industries. Furthermore, microbial source has the best acceptance by people whose religious beliefs (Halal certification and kosher) and eating habits (vegetarian) versus animal sources which are derived with expensive cost from pigs [3, 4]. In general, proteases production from microorganisms is constitutive or partially inducible in nature.…”

Section: Introductionmentioning

confidence: 99%

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

Ahmed

Saleh

Abdel-Hameed

et al. 2019

Heliyon

Self Cite

View full text Add to dashboard Cite

Bacillus megaterium 314 strain was able to utilize agricultural and industrial wastes for metallo-protease production. Orange peel and wheat bran were found as the most suitable carbon and nitrogen sources, respectively. Optimized production process enhanced the enzyme production by 5.1-folds. Glass and glass-ceramic with different particle sizes based on mica were used as inorganic carrier. Protease enzyme was immobilized by covalent bonding and physical adsorption methods on nanoparticle supports. Enzyme physically adsorbed on glass ceramic (particle size 0.71–1.0 mm) had the highest residual activity and the highest immobilization yield. Glass-ceramic was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Immobilized enzyme exhibited activation energy ( E a ) and deactivation rate constant at 60 °C ( k d ) about 1.29 and 1.46-times, respectively lower than free enzyme. Moreover, adsorbed enzyme had higher energy for denaturation ( E d ), half-life ( t 1/2 ), and decimal reduction time ( D ). The thermodynamic parameters of irreversible thermal denaturation for the protease enzyme indicate that immobilized enzyme had higher enthalpy (ΔH°), free energy (ΔG°), and entropy (ΔS°) than free one. There was a significant improvement in the maximum reaction velocity Vmax (2.5-fold), Michaelis constant Km (1.9-fold), and catalytic efficiency Vmax/Km (4.7-fold) values after immobilization indicating the efficiency and effectiveness of immobilization approach.

show abstract

Section: Introductionmentioning

confidence: 99%

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

Ahmed

Saleh

Abdel-Hameed

et al. 2019

Heliyon

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, NiCl 2 and ZnSO 4 showed an inhibitory effect on the milkclotting activity as compared to the control (Skim-milk only). Similarly, Ca 2+ (El-Tanboly et al, 2013), Na + , K + , Mn 2+ and Ca 2+ (Liu and Huang, 2015) and Ca 2+ , Mg 2+ , Mn 2+ (Kumari et al 2016) and Mn 2+ , Ca 2 (Ahmed et al, 2016) were shown a noticeable effect on enhancing the the activity of milk-clotting enzyme from M. pusillus QM 436, acidic protease from Rhizopus stolonifer, MCE from B. subtilis MTCC 10422 and MCE from B. stearothermophilus, respectively. Whereas the addition of Co 2+ , Cd 2+ and Zn 2+ were found to have an inhibitory effect on the activity of MCE from B. subtilis MTCC 10422 (Kumari et al 2016).…”

Section: Discussionmentioning

confidence: 92%

Purification and Characterization of Aspartic Protease Produced fromAspergillus oryzaeDRDFS13 under Solid-State Fermentation

Mamo

Orellana

Yelemane

et al. 2020

Preprint

View full text Add to dashboard Cite

Aspartic proteases (E.C.3.4.23.) are endopeptidases with molecular masses ranging between 30-45 kDa. They depend on aspartic acid residues for their catalytic activity and show maximal activity at low pH. Thus the main objective of the present study was to purify and characterize aspartic protease from locally identified fungi by solid-state fermentation. The aspartic protease in the current study was obtained from A. oryzae DRDFS13 under SSF. The crude enzyme extract was purified by size-exclusion (SEC) and ion-exchange (IEC) chromatography. The protein contents of crude enzyme and IEC fractions were determined by BCA methods while the presence of N-glycosylation was checked using Endo-H. Inhibition studies were conducted using protease inhibitors. The milk-clotting activity (MCA), protease activity (PA); molecular weight and enzyme kinetics were determined using standard methods. Optimum temperature and stability, optimum pH and stability, and the effect of cations on MCA were assessed using standard methods. The maximum MCA (477.11 U/mL) was recorded from IEC fraction A8. The highest specific activity (183.50 U/mg), purification fold (6.20) and yield (9.2%) were also obtained from the same fraction (IEC A8). The molecular weight of 40 kDa was assigned for the purified enzyme (IEC A8). However, its molecular weight was decreased to 30 KDa upon deglycosylation assay which infers that the protein is glycosylated. Incubation of the pure enzyme (IEC A8) with pepstatin A caused a 94 % inhibition on MCA. The dialyzed enzyme showed a Km and Vmax values of 17.50 mM and 1369 U, respectively. The enzyme showed maximum MCA at 60 oC and pH 5.0 with stability at pH 4.5-6.5 and temperature 35-45 oC. Most cat-ions stimulate the activity of the enzyme; moreover, the highest MCA was detected at 50 mM of MnSO4. Furthermore, the results obtained in the present study confirmed that the aspartic protease enzyme produced from A. oryzae DRDFS13 and purified in ion-exchange chromatography could be used as a substitute source of rennet enzyme for cheese production.

show abstract

“…The level of primary proteolysis was considerably greater in Cheese MR (from 3.45% to 11.46%) than in Cheese CR (from 1.83% to 4.12%). Similarly, cheese made with the rennet from B. stearothermophilus had greater WSN content than cheese made with a commercial coagulant due to additional proteolysis caused by the microbial coagulant (Ahmed, Wehaidy, Ibrahim, Abd El Ghani, & El‐Hofi, ). The trend of change with EtOH‐SN during cheese ripening was similar to that with WSN in both cheeses.…”

Section: Resultsmentioning

confidence: 99%

“…In particular, no notable bitterness was detected in Cheese MR though there was more proteolysis taking place in Cheese MR than Cheese CR during ripening, as described above (Figure ). Previously, the rennets from B. stearothermophilus and fungi were shown to cause bitter‐taste defects in different cheeses (Ahmed et al, ; Vishwanatha et al, ). The formation of hydrophobic peptides due to the proteolytic activity of the microbial rennet was thought to cause a bitter taste in cheese (Pino, Prados, Galán, McSweeney, & Fernández‐Salguero, ).…”

Section: Resultsmentioning

confidence: 99%

Change of proteolysis and sensory profile during ripening of Cheddar‐style cheese as influenced by a microbial rennet from rice wine

Zhao

Zheng

Zhang

et al. 2019

Food Science & Nutrition

View full text Add to dashboard Cite

To test the potential of a novel microbial rennet isolated from traditional fermented rice wine for cheese making, Cheddar‐style cheese made with this enzyme was studied for changes in composition, proteolysis, and sensory profile during 90 days of ripening in comparison with a control cheese made with a commercial rennet. The initial proteolysis assay of the microbial rennet on milk proteins indicated a notable increase in the hydrolysis of casein components (α‐, β‐, and κ‐caseins) but no effect on whey proteins upon increasing the concentration of the enzyme. Correspondingly, compared to cheese made with commercial rennet, the use of the microbial rennet in Cheddar‐style cheese resulted in significantly higher primary and secondary proteolysis in the later stages of ripening (60–90 days ripening) and thus a softer texture and the formation of more volatile compounds and free amino acids (FAAs) despite its lower moisture content (41.7%, w/w). Though the cheese made with the microbial rennet was found to contain bitter‐taste FAAs (1,000 mg/100 g), the combined effect of other‐taste FAAs, including sweet (231 mg/100 g), umami (225 mg/100 g), and tasteless (361 mg/100 g) FAAs, in the cheese attenuated the bitter taste of the cheese. This analysis was in accordance with the sensory evaluation, which showed no significantly different sensory scoring between the cheeses made with the microbial and commercial rennets. The present study demonstrated a novel approach to evaluate the bitter taste of ripened cheese. The results of this study suggest the potential of the microbial rennet from rice wine to serve as a new source of milk‐clotting agents in cheese making.

show abstract

Novel milk-clotting enzyme from Bacillus stearothermophilus as a coagulant in UF-white soft cheese

Cited by 69 publications

References 19 publications

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

Purification and Characterization of Aspartic Protease Produced fromAspergillus oryzaeDRDFS13 under Solid-State Fermentation

Change of proteolysis and sensory profile during ripening of Cheddar‐style cheese as influenced by a microbial rennet from rice wine

Contact Info

Product

Resources

About