Small scale production and characterization of xanthan gum synthesized by local isolates of Xanthomonas campestris.

Xanthan gum is a commercially important microbial exopolysaccharide (EPS) produced by Xanthomonas campestris. X. campestris is a plant pathogen causing various plant diseases such as black rot of crucifers, bacterial leaf blight and citrus canker disease resulting in crop damage. In this study, we isolated efficient local bacterial isolates which are capable to produce xanthan gum utilizing different sources of carbon (maltose, sucrose and glucose). Bacterial isolates from different plant leaves and fruits were identified as Xanthomonas campestris based on their morphological and biochemical characteristics. Among the 23 isolates, 70% were capable of producing gum. Taro plant, considered as new bacterial host, also have the capability to produce xanthan gum. Production conditions of xanthan gum and their relative viscosity by these bacterial isolates were optimized using basal medium containing commercial carbon and nitrogen sources and various temperature and rotation. Highest level of xanthan gum (18.286 g/l) with relative viscosity (7.2) was produced (Host, Citrus macroptera) at 28°C, pH 7.0, 150 rpm using sucrose as a carbon source at orbital shaker. Whereas, in lab fermenter, same conditions gave best result (19.587 g/l gum) with 7.8 relative viscosity. Chilled alcohol (96%) was used to recover the xanthan gum. FTIR studies also carried out for further confirmation of compatibility by detecting the chemical groups.

Antioxidant, Brine Shrimp Lethality and Antimicrobial Activities of Methanol and Ethyl-Acetate Extracts of Citrus macroptera Montr. Fruit Using In vitro Assay Models.

Aims: To study and evaluate In vitro antioxidant, brine shrimp lethality and antimicrobial activities of both methanol and ethyl-acetate extracts of Citrus macroptera Montr. Fruit (Family-Rutaceae). Study Design: In vitro antioxidant, brine shrimp lethality and antimicrobial activities. Place and Duration of Study: Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342. The study was carried out from November 2013 to January 2014. Methodology: In vitro antioxidant activities of the extracts were studied using DPPH radical scavenging assay, NO scavenging assay, total phenol, total flavonoid content, total antioxidant capacity, total tannin content, lipid peroxidation by TBA, lipid peroxidation in human erythrocyte cell, reducing power capacity and cupric reducing capacity assays. Lethality bioassay was performed on Artemia salina Leach nauplii. Antimicrobial activity was investigated by disc diffusion technique. Results: Methanol extract showed better activity than ethyl acetate extract in DPPH, NO, lipid peroxidation by TBA, reducing power capacity assay, total phenol, total flavonoid and total antioxidant capacity assays while ethyl –acetate extract showed more potency than methanol extract in total tannin content, cupric reducing capacity and lipid peroxidation in human erythrocyte assays. In brine shrimp bioassay both extracts showed promising lethal activity but methanol extract was found to be more potent than ethyl acetate extract (χ2=39.874, P<0.0001). In disc diffusion technique among six bacterial species, ethyl acetate extract showed broad spectrum antimicrobial activity against two gram positive Bacillus sublitis and Staphylococcus aureus and one gram negative Escherichia coli. Conclusion: The results demonstrate that methanol and ethyl-acetate extracts of C. macroptera fruit can be used as potential antioxidant, cytotoxic and antimicrobial agents. That is why extensive researches are necessary to search for active principles responsible for these activities.

In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera Montr. fruit

Objective: To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr. fruit in α-amylase inhibitory activity (in vitro) and hypoglycemic activity in normal and glucose induced hyperglycemic rats (in vivo). Methods: Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents, α-amylase inhibitory activity, and hypoglycemic effect in normal rats and glucose induced hyperglycemic rats. Results: Presence of saponin, steroid and terpenoid were identified in the extract. The results showed that fruit extract had moderate α-amylase inhibitory activity [IC

In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera Montr. fruit

Objective: To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr. fruit in α-amylase inhibitory activity (in vitro) and hypoglycemic activity in normal and glucose induced hyperglycemic rats (in vivo). Methods: Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents, α-amylase inhibitory activity, and hypoglycemic effect in normal rats and glucose induced hyperglycemic rats.Results:showed that fruit extract had moderate α-amylase inhibitory activity [IC50 value=(3.638±0.190) mg/mL] as compared to acarbose. Moreover at 500 mg/kg and 1 000 mg/kg doses fruit extract significantly (P<0.05 and P<0.01 respectively) reduced fasting blood glucose level in normal rats as compared to glibenclamide (5 mg/kg). In oral glucose tolerance test, 500 mg/kg dose significantly reduced blood glucose level (P<0.05) at 2 h but 1000 mg/kg dose significantly reduced blood glucose level at 2 h and 3 h (P<0.05 and P<0.01 respectively) whereas glibenclamide (5 mg/kg) significantly reduced glucose level at every hour after administration. Overall time effect is also considered extremely significant with F value=23.83 and P value=0.0001 in oral glucose tolerance test.Conclusion:These findings suggest that the plant may be a potential source for the development Presence of saponin, steroid and terpenoid were identified in the extract. The results of new oral hypoglycemic agent.

In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera Montr. fruit

<p><b>OBJECTIVE</b>To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr.fruit in α-amylase inhibitory activity (in vitro) and hypoglycemic activity in normal and glucose induced hyperglycemic rats (in vivo).</p><p><b>METHODS</b>Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents, α-amylase inhibitory activity, and hypoglycemic effect in normal rats and glucose induced hyperglycemic rats.</p><p><b>RESULTS</b>Presence of saponin, steroid and terpenoid were identified in the extract. The results showed that fruit extract had moderate α-amylase inhibitory activity [IC50 value=(3.638±0.190) mg/mL] as compared to acarbose. Moreover at 500 mg/kg and 1 000 mg/kg doses fruit extract significantly (P<0.05 and P<0.01 respectively) reduced fasting blood glucose level in normal rats as compared to glibenclamide (5 mg/kg). In oral glucose tolerance test, 500 mg/kg dose significantly reduced blood glucose level (P<0.05) at 2 h but 1 000 mg/kg dose significantly reduced blood glucose level at 2 h and 3 h (P<0.05 and P<0.01 respectively) whereas glibenclamide (5 mg/kg) significantly reduced glucose level at every hour after administration. Overall time effect is also considered extremely significant with F value=23.83 and P value=0.0001 in oral glucose tolerance test.</p><p><b>CONCLUSION</b>These findings suggest that the plant may be a potential source for the development of new oral hypoglycemic agent.</p>