Neeta Sharma

Influence of inoculation of arsenic-resistant Staphylococcus arlettae on growth and arsenic uptake in Brassica juncea (L.) Czern. Var. R-46

An arsenic hypertolerant bacterium was isolated from arsenic contaminated site of West Bengal, India. The bacteria was identified as Staphylococcus arlettae strain NBRIEAG-6, based on 16S rDNA analysis. S. arlettae was able to remove arsenic from liquid media and possesses arsC gene, gene responsible for arsenate reductase activity. The biochemical profiling of the isolated strain showed that it had the capacity of producing indole acetic acid (IAA), siderophores and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. Furthermore, an experiment was conducted to test the effect of S. arlettae inoculation on concurrent plant growth promotion and arsenic uptake in Indian mustard plant [Brassica juncea (L.) Czern. Var. R-46] when grown in arsenic spiked (5, 10 and 15 mg kg(-1)) soil. The microbial inoculation significantly (p<0.05) increased biomass, protein, chlorophyll and carotenoids contents in test plant. Moreover, as compared to the non-inoculated control, the As concentration in shoot and root of inoculated plants were increased from 3.73 to 34.16% and 87.35 to 99.93%, respectively. The experimental results show that the plant growth promoting bacteria NBRIEAG-6 has the ability to help B. juncea to accumulate As maximally in plant root, and therefore it can be accounted as a new bacteria for As phytostabilization.

PRESERVATION OF DRIED FRUITS AND NUTS FROM BIODETERIORATION BY NATURAL PLANT VOLATILES

Studies were carried out to optimize production of nucleopolyhedrovirus of American bollworm,Helicoverpa armigera (Hübner), by treating larvae individually with an inoculum dose that allowed maximal larval growth and also gave the highest occlusion bodies (OB) yield/larva. The maximum virus yield of 12.2x 109 OB/larva was obtained when 6-day-old larvae were fed individually with a dose of 1 x 103 OB. Topical spiracular treatment of larvae as old as 8 days with 10 μ of 2x 107 OB ml-1 gave the highest yield, of 15.2x 109 OB from 13-day-old larvae, of 12.8x 108 OB from prepupae and of 1.49x 108 OB from pupae at the time of their death. These studies showed that dietary inoculum is the best route for 6-day-old larvae and topical spiracular treatment is the best for 8-day-old larvae.Studies were carried out to optimize production of nucleopolyhedrovirus of American bollworm,Helicoverpa armigera (Hubner), by treating larvae individually with an inoculum dose that allowed maximal larval growth and also gave the highest occlusion bodies (OB) yield/larva. The maximum virus yield of 12.2x 109 OB/larva was obtained when 6-day-old larvae were fed individually with a dose of 1 x 103 OB. Topical spiracular treatment of larvae as old as 8 days with 10 μ of 2x 107 OB ml-1 gave the highest yield, of 15.2x 109 OB from 13-day-old larvae, of 12.8x 108 OB from prepupae and of 1.49x 108 OB from pupae at the time of their death. These studies showed that dietary inoculum is the best route for 6-day-old larvae and topical spiracular treatment is the best for 8-day-old larvae.

A combination of the yeast Candida utilis and chitosan controls fruit rot in tomato caused by Alternaria alternata (Fr.) Keissler and Geotrichum candidum Link ex Pers.

Summary The antifungal activity of chitosan was tested in vitro against Alternaria alternata and Geotrichum candidum, two major post-harvest pathogens of tomato. Chitosan, at all concentrations, inhibited spore germination in A. alternata and G. candidum. Survival of the yeast biocontrol agent, Candida utilis, in chitosan solution was also studied in vitro, as well as in fruit wounds. Chitosan did not adversely affect the growth of C. utilis. In fruit wounds, populations of C. utilis with or without chitosan increased to the target level (107 CFU per wound) within 7 d, and thereafter became stable. In in vitro studies, populations of C. utilis increased in 0.25% (w/v) chitosan solution; while in 0.5% (w/v) and 1% (w/v) solutions, populations dropped initially, but resumed growth within 24 h. The addition of 0.25% (w/v) chitosan solution to a cell suspension of C. utilis significantly enhanced its efficacy in controlling post-harvest decay of tomato compared with treatments of C. utilis, or 0.25% (w/v) or 0.5% (w/v) chitosan alone. The efficacy of a combination of C. utilis and chitosan was not increased by increasing the concentration of chitosan from 0.25% (w/v) to 0.5% (w/v).

Management of Pathogens of Stored Cereal Grains

Biodeterioration of grains due to pests such as insect infestation and molds is a chronic problem in tropical and subtropical countries. This problem is aggravated due to the hot and humid climate. Consumption of infected grains induces hazardous health effects causing hepatic carcinoma and other serious disorders. Because of the high consumption of grains protection and management is mandatory. Traditionally, safe storage of harvested produce is done by carefully selecting the storage site, using proper storage structures, cleaning and fumigation. Safe storage also involves proper aeration of grains, physical separation of infected grains, drying, irradiation and heat treatment. Synthetic pesticides have been used for protection of stored food grain due to good availability. The application of fungicides to grains after harvest to reduce decay has been increasingly impeded due to: the development of resistance to many key pesticides; the lack of alternative pesticides; toxicity and negative public reception.

Antifungal efficacy of herbs

Candida carriage was reported to be common in oral cancer patients, with C. albicans being the predominant species. The prevalence of diseases caused by Candida species have been found to increase in recent years. AIM The aim of our study was to find the antifungal activities at MIC of selected fifteen plant leaves extracts prepared in three different solutions (methanol and ethanol) against the opportunistic pathogen Candida albicans isolated from oral cavity infections. It may also help the clinician to treat the patient not only for the particular lesion that is present, but also to treat the infection by Candida albicans so as to reduce its potential to malignant transformation. Material n methods: Leaves extract of selected plant prepared in methanolic and eethanolic solution have been chosen for the investigation of in vitro antifungal activity which acts as expectorant and not having toxic properties on humans while for comparison or control, antifungal drugs have been taken. Results showed that Candida albicans shows most sensitivity towards the standard antibiotic cotrimoazol but very less towards other drugs like Fluconazole, minocycline, erythromycin respectively which indicated Candida albicans shows some resistance character towards drugs while the herbal extracts of Lawsonia inermis, Withania somnifer, Curcuma longa, Cymbopogon citrates and Zingiber officinale gives the best inhibitory effect and they have the potential to control growth of Candida albicans.

ANTIFUNGAL ACTIVITY OF DMSO EXTRACTS OF TEN SELECTED HERBS USED FOR THE TREATMENT OF ORAL CAVITY INFECTIONS WITH REFERENCE TO ORAL CARCINOMA

Introduction : Candida albicans, a diploid fungus also a casual agent of opportunistic oral infections in humans and is traditionally being treated using herbs. Due to increase in the antibiotic-resistant strains of microorganisms, traditional plants are being investigated for their antibacterial and medicinal values. Aim: The aim of the present work was to explore the antimicrobial activities of selected plant leaves extracts against the pathogen Candida albicans which is also be responsible for causing oral cancer disease in recent studies. The aim of this study was to assess the antifungal activity of plant leaves extracts against Candida albicans and to study the inhibitory effect of chemical antifungal agents or drugs and elements of tooth pastes on Candida albicans pathogen isolated from oral cavity to compare with herbal plants extracts. Material n methods: In present study, leaves extract of ten selected plant prepared in DMSO solution have been chosen for the investigation of in vitro antifungal activity which acts as expectorant and not having toxic properties on humans while for comparison or control, antifungal drugs have been taken. Results: Results showed that Candida albicans shows most sensitivity towards the standard antibiotic cotrimoazol but very less towards other drugs like Fluconazole, minocycline, erythromycin respectively which indicated Candida albicans shows some resistance character towards drugs while the herbal extracts of Lawsonia inermis, Withania somnifer, Curcuma longa, Cymbopogon citrates and Zingiber officinale gives the best inhibitory effect and they have the potential to control growth of Candida albicans. Conclusion: The present investigation was carried out to investigate the chemical and therapeutically potential by evaluating phytochemical and antifungal activity of the fresh leaves extracts. These findings will further help to develop the new antifungal drugs from these herbs or they can also be use in tooth pastes, oral ointments etc. for treatment of oral diseases at cheapest rate by inhibiting the growth of Candida albicans, an opportunistic fungal pathogen.