METHODS AND RESULTS: The results showed that the bioprocess of T. harzianum K179 bioagent production in a laboratory bioreactor on the medium with optimal composition (dextrose 10 g l-1, soy flour 6.87 g l-1, K2HPO4 1.51 g l-1, KCl 0.5 g l-1, and MgSO4 × 7H2O 0.5 g l-1), at stirring speed of 1.75 × g and aeration intensity of 1.5 vvm, can be shortened from 96 to 36 h. The results of bioprocess economic analysis showed that with a 25-year project lifetime and an investment payback time of 7.58 years, this project represents an economically viable system.
CONCLUSIONS: Complete analysis of the bioprocess of T. harzianum K179 biocontrol agent production showed that the biologically produced preparation can be competitive on the market with synthetic preparations.
MATERIALS AND RESULTS: Four bioformulations consisting of dry (pesta granules, talc powder and alginate beads) and liquid formulations were evaluated for their ability to control Foc-TR4, sustain microbial populations after application and maintain microbial stability during storage. All tested bioformulations reduced disease severity (DS) by more than 43·00% with pesta granules producing the highest reduction in DS by 66·67% and the lowest area under the disease progress curve value (468·75) in a glasshouse trial. Microbial populations of DRB1 and CBF2 were abundant in the rhizosphere, rhizoplane and within the roots of bananas after pesta granules application as compared to talc powder, alginate beads and liquid formulations 84 days after inoculation (DAI). The stability of both microbial populations after 180 days of storage at 4°C was the greatest in the pesta granule formulation.
CONCLUSION: The pesta granule formulation was a suitable carrier of biological control agents (BCA) without compromising biocontrol efficacy, microbial population and storage stability as compared to other bioformulations used in this study.
SIGNIFICANCE AND IMPACT OF THE STUDY: Pesta granules could be utilized to formulate BCA consortia into biofertilizers. This formulation could be further investigated for possible applications under agricultural field settings.
METHODS AND RESULTS: Rice bran, biochar, empty fruit bunches, coconut fibres, compost, top soil and mixed soil were evaluated as media for mass multiplication of T. asperellum, which is effective in controlling plant pathogens. Yielding the most colony forming units (CFU) among the media, coconut fibre was deemed most suitable for promoting sporulation. After 120 days on the medium, T. asperellum B1902 produced 9·053 × 105 CFU per gram coconut fibre; oil palm empty fruit bunches was second highest (7·406 × 105 CFU per gram). In field tests of T. asperellum B1092 against F. oxysporum f. sp lycopersici (causing Fusarium wilt of cherry tomato), B1092 significantly promoted plant growth compared to the control. The efficacy of this formulation resulted in increased growth of roots and shoots tomato plants and total lycopene, sugar, K, N, Ca, P and Mg content after 120 days.
CONCLUSIONS: Trichoderma asperellum B1092 showed great field potential for improving productivity and quality of tomatoes and in controlling Fusarium wilt of cherry tomato.
SIGNIFICANCE AND IMPACT OF THE STUDY: This innovative approach using a cheap agro-waste to control the persistent soil-borne Fusarium pathogen of cherry tomato should increase soil survival rate of Trichoderma and has potential for upscaling in the field for other crops.
METHODS AND RESULTS: Lactic acid bacteria strains were isolated and examined for acid tolerance, bile salt resistance and hypocholesterolemic properties. Among the isolates, Lactobacillus plantarum TAR4 showed the highest cholesterol reduction ability (48·01%). The focus in the in vivo trial was to elucidate the cholesterol balance from findings pertaining to serum cholesterol reduction in rat model fed with high fat diet via oral administration. Rats fed with high-cholesterol diet supplemented with Lact. plantarum TAR4 showed significant reduction in serum total cholesterol (29·55%), serum triglyceride (45·31%) and liver triglyceride (23·44%) as compared to high-cholesterol diet (HCD) group. There was a significant increment in faecal triglyceride (45·83%) and faecal total bile acid (384·95%) as compared to HCD group.
CONCLUSIONS: The findings showed that probiotic Lact. plantarum TAR4 supplementation reduced the absorption of bile acids for enterohepatic recycling and increased the catabolism of cholesterol to bile acids and not by suppressing the rate of cholesterol synthesis.
SIGNIFICANCE AND IMPACT OF STUDY: Probiotic supplements could provide a new nonpharmacological alternative to reduce cardiovascular risk factors.
METHODS AND RESULTS: Ag-NPs were synthesized using a chemical reduction method and characterized with respect to their surface plasmon resonance, surface morphology via transmission electron microscopy (TEM) and dynamic light scattering (DLS). The bacterial surface was targeted using 20 nm Ag-NPs conjugated with an anti-protein A antibody. Labelled bacteria were irradiated with blue visible laser at 2·04 W/cm2 . The antibacterial activity of functionalized Ag-NPs was investigated by fluorescence microscopy after irradiation, and morphological changes in S. aureus after laser treatment were assessed using scanning electron microscopy (SEM). The laser-irradiated, functionalized Ag-NPs exhibited significant bactericidal activity, and laser-induced bacterial damage was observed after 10 min of laser irradiation against S. aureus. The fluorescence microscopic analysis results supported that bacterial cell death occurred in the presence of the functionalized Ag-NPs.
CONCLUSIONS: The results of this study suggest that a novel method for the preparation of functionalized nanoparticles has potential as a potent antibacterial agent for the selective killing of resistant disease-causing bacteria.
SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that Ag-NPs functionalized with a specific antibody, could be used in combination with laser radiation as a novel treatment to target resistant bacterial and fungal pathogens with minimal impact on normal microflora.