ABSTRACT
Introduction: Honey bee gut microbiota have an important role in host health, nutrition, host-symbiont interaction, and interaction behavior with the surrounding environment. Recent discoveries of strain-level variation, characteristics of protective and nutritional capabilities, and reports of eco-physiological significance to the microbial community have emphasized the importance of honey bee gut microbiota. Many regions of Asia and Africa are inhabited by the dwarf honey bee, Apis florea. Studying its microflora and potential for pollination is therefore of foremost importance. Methods: In the present investigation, we aimed to explore the gut bacteriobiome composition of two distinct honey bee species, Apis florea and Apis cerana indica using high throughput sequencing. Functional predictions of bee gut bacterial communities using PICRUSt2 was carried out. Results and discussion: The phylum Proteobacteria dominated the bacterial community in both A. cerana indica (50.1%) and A. florea (86.7%), followed by Firmicutes (26.29 and 12.81%), Bacteroidetes (23.19 and 0.04%) and Actinobacteria (0.4 and 0.02%) respectively. The gut bacteria of A. cerana indica was more diverse than that of A. florea. The observed variations in bacterial genomic diversity among these critical pollinator species may have been influenced by the apiary management techniques, ecological adaptation factors or habitat size. These variations can have a significant effect in understanding host-symbiont interactions and functioning of gut microbiota highlighting the importance of metagenomic survey in understanding microbial community ecology and evolution. This is the first comparative study on variation in bacterial diversity between two Asian honey bees.
ABSTRACT
In this study, we report the biochemical characterization of a novel serine protease from seeds of Cucumis maderaspatensis, aimed with assessing the anticoagulant and antiplatelet activities. The purified serine protease was obtained by subjecting the seed extract to ammonium sulphate precipitation followed by anion exchange and gel filtration chromatography. Twenty seven-fold purification with the specific activity of 884.2 U/mg of protease activity was obtained. The characterization of the novel protease enzyme activity for optimum temperature, pH and effect of different protease inhibitors and metal ions were measured using caseinolytic assay and casein zymogram. The relative molecular mass of the novel neutral serine protease (CmSP) is ~ 32 kDa. Its anticoagulant was determined by assessing the delay in plasma re-calcification time in both platelet-rich and platelet-poor plasma. The antiplatelet activity of serine protease was demonstrated by inhibition of agonists induced platelet aggregation; it was in the order of Epinephrine > Adenosine tri phosphate. Further studies would decipher the mechanism of action to understand its therapeutic potential as an antiplatelet and anticoagulant molecule.
ABSTRACT
Pectin methylesterase (PME) extracted from muskmelon was purified by anion exchange chromatography. The specific activity of purified enzyme was 152.01 U/mg and relative molecular weight was ~69,000 Da. Methylesterase was characterized for various physicochemical factors to designate its suitability in the food industry applications. The optimum temperature of the enzyme was 30°C and is thermally stable between the temperature ranges of 15-65°C with critical temperature for stability being >65°C. Thermal inactivation first order kinetics and thermodynamic parameters in temperature range (45-65°C) favors stability of PME and at 75°C complete inactivation of enzyme was observed indicating the unstable nature of enzyme over >65°C. Activation energy (Ea ) and Z values of thermal inactivation were found to be 100.108 kJ/mol and 2.05°C, respectively. About 0.1 M NaCl is essential for enzyme to attain the maximum activity. The enzyme lost activity in presence of divalent calcium (Ca2+ ) and magnesium (Mg2+ ) ions. PRACTICAL APPLICATIONS: Pectin methylesterase (EC3.1.1.11) are an important class of enzymes expressed in plants and microbes and they bring about the de-methylesterification on pectin substrate. Up to ~13% degree of esterification of pectin was observed with muskmelon PME enzyme treatment. The de-methylesterified pectin thus prepared was subjected for gelation in presence of Ca2+ ions and above 0.5% of demethylesterified pectin stable calcium pectate gels were produced. The study demonstrates the suitability of muskmelon PME extracted from biowaste in food applications with good gelling property.
