Dev Kamal - Academia.edu (original) (raw)

Papers by Dev Kamal

Research paper thumbnail of Characterization of novel polymorphic microsatellite markers in Dactylorhiza hatagirea: a critically endangered orchid species from western Himalayas

Conservation Genetics Resources, 2014

Dactylorhiza hatagirea (D. Don) Soo, family Orchidaceae is an endangered medicinal herb inhabitin... more Dactylorhiza hatagirea (D. Don) Soo, family Orchidaceae is an endangered medicinal herb inhabiting higher altitudes of western Himalayas. Due to reckless exploitation for its roots, it is of high conservation concern. In the present study fifteen microsatellites were developed and characterized across twenty collections of D. hatagirea. The total numbers of alleles amplified by these microsatellites were 64 with an average of 4.2 alleles per marker. Average observed and expected heterozygosity values for polymorphic loci were 0.623 and 0.631, respectively. Mean polymorphism information content value of the polymorphic markers was 0.532. Of the fourteen polymorphic microsatellites, 7 deviated from Hardy–Weinberg equilibrium. Microsatellites reported here can be utilized to address questions related to genetic characteristics in this species.

Research paper thumbnail of Comparative analysis of capsaicin in twenty nine varieties of unexplored Capsicum and its antimicrobial activity against bacterial and fungal pathogens

Journal of Medicinal Plants Research

In this study, the capsaicin content of chile pepper extracts from 29 unexplored varieties of Cap... more In this study, the capsaicin content of chile pepper extracts from 29 unexplored varieties of Capsicum (twenty five varieties of Capsicum chinense and five of Capsicum annuum) was quantified and correlated with the antimicrobial potential against bacterial and fungal pathogens. The capsaicin content and bactericidal activity against numerous human pathogens (Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Candida albicans) was compared to identify the most effective chile pepper varieties in the treatment of bacterial and fungal pathogens. The capsaicin content of the tested varieties varied from 29 to 42,633 ppm (139-682,135 SHU). On average, the fruits of C. chinense cultivars contained much higher concentrations of capsaicin than C. annuum cultivars. The undiluted chile peppers extracts with capsaicin concentrations greater than 25,000 SHU demonstrated bactericidal and antifungal effects. Overall, it was determined that L. monocytogenes and S. aureus were more susceptible to the antimicrobial effects of capsaicin than Salmonella and E. coli O157:H7, while C. albicans was markedly more susceptible than all bacterial species examined. The extract of the sixth most pungent cultivar, C. chinense Bhut Jolokia Red, showed the greatest antimicrobial potency of all screened peppers. The antimicrobial activity of pepper extracts was not directly correlated with increasing capsaicin concentrations, indicating that various Capsicum cultivars may possess distinct capsaicin derivatives. This is the first study which showed the relationship between capsaicin contents in different Capsicum varieties and their antimicrobial potential, and opens avenues in the study of capsaicin derivatives and their role in health and medicines.

Research paper thumbnail of Isolation and Characterization of Psychrotolerant Serratia Quinivorans Strains Secreting β-D-galactosidase

adapted and extracellular β-D-galactosidase (EC 3.2.1.23) with high specific activity has potenti... more adapted and extracellular β-D-galactosidase (EC 3.2.1.23) with high specific activity has potential in food industry. Two psychrophlic bacterial isolates (A5-2 and B8) were screened from soil collected from permanent glaciers of Himachal Pradesh, India. Both A5-2 and B8 isolates showed growth between 4-25℃, but not at temperature higher than 30℃, hence classified as psychrotolerants. Biochemical characteristics and 16S rDNA sequencing identified the isolates as Serratia quinivorans A5-2 and Serratia quinivorans B8, and deposited in NCBI GenBank under accesion numbers KJ 176660 and KJ 176661, respectively. The cold active, extracellular β-D-galactosidase activity of A5-2 isolate was three fold higher compared to its intracellular activity. Comparatively, the B8 bacterial showed negligible intracellular activity, and its extracellular activity was two folds higher as compared to that of A5-2 isolate. Interestingly, growth and β-D-galactosidase activity of A5-2 was enhanced in lactose supplemented medium;whereas, growth of B8 isolate was unaffected and its β-D-galactosidase activity was enhanced when grown in lactose supplemented medium. β-D-galactosidase activity was also increased, when the isolates were grown in galactose supplementation medium, but decreased when grown in the presence of glucose. The presence of milk sugars like lactose, glucose, or galactose, or the milk metal ions, namely Ca 2+ and Na + ions did not inhibit the activity of β-D-galactosidase.

Research paper thumbnail of Characterization of novel polymorphic microsatellite markers in Dactylorhiza hatagirea: a critically endangered orchid species from western Himalayas

Conservation Genetics Resources, 2014

Dactylorhiza hatagirea (D. Don) Soo, family Orchidaceae is an endangered medicinal herb inhabitin... more Dactylorhiza hatagirea (D. Don) Soo, family Orchidaceae is an endangered medicinal herb inhabiting higher altitudes of western Himalayas. Due to reckless exploitation for its roots, it is of high conservation concern. In the present study fifteen microsatellites were developed and characterized across twenty collections of D. hatagirea. The total numbers of alleles amplified by these microsatellites were 64 with an average of 4.2 alleles per marker. Average observed and expected heterozygosity values for polymorphic loci were 0.623 and 0.631, respectively. Mean polymorphism information content value of the polymorphic markers was 0.532. Of the fourteen polymorphic microsatellites, 7 deviated from Hardy–Weinberg equilibrium. Microsatellites reported here can be utilized to address questions related to genetic characteristics in this species.

Research paper thumbnail of Comparative analysis of capsaicin in twenty nine varieties of unexplored Capsicum and its antimicrobial activity against bacterial and fungal pathogens

Journal of Medicinal Plants Research

In this study, the capsaicin content of chile pepper extracts from 29 unexplored varieties of Cap... more In this study, the capsaicin content of chile pepper extracts from 29 unexplored varieties of Capsicum (twenty five varieties of Capsicum chinense and five of Capsicum annuum) was quantified and correlated with the antimicrobial potential against bacterial and fungal pathogens. The capsaicin content and bactericidal activity against numerous human pathogens (Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Candida albicans) was compared to identify the most effective chile pepper varieties in the treatment of bacterial and fungal pathogens. The capsaicin content of the tested varieties varied from 29 to 42,633 ppm (139-682,135 SHU). On average, the fruits of C. chinense cultivars contained much higher concentrations of capsaicin than C. annuum cultivars. The undiluted chile peppers extracts with capsaicin concentrations greater than 25,000 SHU demonstrated bactericidal and antifungal effects. Overall, it was determined that L. monocytogenes and S. aureus were more susceptible to the antimicrobial effects of capsaicin than Salmonella and E. coli O157:H7, while C. albicans was markedly more susceptible than all bacterial species examined. The extract of the sixth most pungent cultivar, C. chinense Bhut Jolokia Red, showed the greatest antimicrobial potency of all screened peppers. The antimicrobial activity of pepper extracts was not directly correlated with increasing capsaicin concentrations, indicating that various Capsicum cultivars may possess distinct capsaicin derivatives. This is the first study which showed the relationship between capsaicin contents in different Capsicum varieties and their antimicrobial potential, and opens avenues in the study of capsaicin derivatives and their role in health and medicines.

Research paper thumbnail of Isolation and Characterization of Psychrotolerant Serratia Quinivorans Strains Secreting β-D-galactosidase

adapted and extracellular β-D-galactosidase (EC 3.2.1.23) with high specific activity has potenti... more adapted and extracellular β-D-galactosidase (EC 3.2.1.23) with high specific activity has potential in food industry. Two psychrophlic bacterial isolates (A5-2 and B8) were screened from soil collected from permanent glaciers of Himachal Pradesh, India. Both A5-2 and B8 isolates showed growth between 4-25℃, but not at temperature higher than 30℃, hence classified as psychrotolerants. Biochemical characteristics and 16S rDNA sequencing identified the isolates as Serratia quinivorans A5-2 and Serratia quinivorans B8, and deposited in NCBI GenBank under accesion numbers KJ 176660 and KJ 176661, respectively. The cold active, extracellular β-D-galactosidase activity of A5-2 isolate was three fold higher compared to its intracellular activity. Comparatively, the B8 bacterial showed negligible intracellular activity, and its extracellular activity was two folds higher as compared to that of A5-2 isolate. Interestingly, growth and β-D-galactosidase activity of A5-2 was enhanced in lactose supplemented medium;whereas, growth of B8 isolate was unaffected and its β-D-galactosidase activity was enhanced when grown in lactose supplemented medium. β-D-galactosidase activity was also increased, when the isolates were grown in galactose supplementation medium, but decreased when grown in the presence of glucose. The presence of milk sugars like lactose, glucose, or galactose, or the milk metal ions, namely Ca 2+ and Na + ions did not inhibit the activity of β-D-galactosidase.