Endophytic bacteria promote biomass production and mercury-bioaccumulation of Bermuda grass and Indian goosegrass.

Plant growth-promoting endophytic bacteria can potentially improve the biomass production of Hg-accumulating grasses, resulting in improved Hg extraction from contaminated soils. This study aimed to analyze the effect of inoculation of Hg-resistant endophytic bacteria (i) Jeotgalicoccus huakuii (B1) and (ii) Bacillus amyloliquefaciens (B2), as single and consortium inoculant, on biomass production and Hg bioaccumulation of Bermuda grass (R1) and Indian goosegrass (R2) planted as monoculture and mixed cropping. The grass seeds were surface-sterilized before the inoculation. Both inoculated seeds with B1 and B2 (treatments) and uninoculated seeds were sown separately in sterilized sand. Grass seedlings of both treatments and control were replanted in the washed and sterilized sand medium, spiked with HgCl2 (100 mg kg-1). A subset of grass was harvested at 0, 4, 6, and 10 weeks after planting to measure biomass production and Hg bioaccumulation. The results showed that bacterial inoculation enhanced the grass biomass by 52.68% and Hg bioaccumulation by 47.76%. Mercury residue of Hg-spiked sand treated with the bacterial consortium was reduced by 80%. This suggests that endophytic bacteria can improve grass biomass production and enhance Hg bioaccumulation in grass biomass.

Toxicity test of flavonoid compounds from the leaves of Dendrophthoe pentandra (L.) Miq. using in vitro culture cell models.

Background and Aim: The flavonoids from mistletoe are thought to have antimicrobial action. This encouraging finding supports the benefits of medicinal plants as a substitute for synthetic antimicrobials, thus promoting healthy lifestyles. In contrast, it is known that the use of topical drug formulations made from flavonoids of mistletoe (Dendrophthoe pentandra (L.) Miq. Loranthaceae) with Indonesian name, Benalu duku (BD) is required in skin cell irritation. This study aimed to assess the toxic effects of the flavonoid substances of BD, as an initial screening. Materials and Methods: A myeloma cell line was cultured in Roswell Park Memorial Institute medium, and the Baby Hamster Kidney clone 12 (BHK21) cell line was cultured in Dulbecco's Modified Eagle's Medium from stock (±9 × 107 cells/mL), and 1.2 mL of culture were distributed into each well of a microtiter plate. Subsequently, 0.2 mL of serially diluted flavonoid compounds (0.5-3 µg/mL) were added to 12 wells for each concentration, as trial groups (including control groups), followed by a 2-day incubation. Observations were performed based on the cytopathic effect (CPE) using an inverted microscope at a magnification of 100×. Results: Cytopathic effect was detected on the microtiter plate wells for the groups of myeloma and BHK21 cells at a flavonoid concentration of 0.5 µg/mL-3 µg/mL. Conclusion: Flavonoid compounds from BD were safely used for topical treatment of cancer cells at a concentration <2.491 µg/mL, whereas for non-cancerous cells, a concentration <2.582 µg/mL was sufficient (p < 0.05).

THE COMPARING OF ANTIMICROBIAL ACTIVITY OF CSN1S2 PROTEIN OF FRESH MILK AND YOGHURT GOAT BREED ETHAWAH INHIBITED THE PATHOGENIC BACTERIA.

BACKGROUND: Goat milk is reported to have antimicrobial activity of several pathogen bacteria that contained on food materials. The research related with antimicrobial activity of Alpha-S2 casein from goat milk is relatively less than other casein components. Herein, we reported the antimicrobial activity of caprine Alpha-S2 Casein (CSN1S2) protein from Ethawah breed goat milk and yoghurt in Gram positive (Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus) and negative pathogen bacteria (Escherichia coli, Salmonella typhi and Shigella flexneri). Those bacteria were known as pathogens that caused gastrointestinal infection. METHODS: Serial dilution and agar diffusion analysis with three different concentrations of caprine CSN1S2, 1.25 mg/ml, 2.5 mg/ml, and 5 mg/ml were used to test the inhibition effect of protein on the viability of bacteria cells. The inhibitory activity of caprine CSN1S2 was based on dose dependent manner. Agar diffusion analysis was showed the larger diameter of clear zone at B. cereus and S. flexneri. RESULTS: The serial dilution analysis was shown the inhibition of almost in all groups of bacteria with concentration 5 mg/ml higher by CSN1S2 protein of goat fresh milk than yogurt. The inhibitory activity caprine CSN1S2 protein of fresh milk was shown a vary inhibition clear zone with optimal concentration 5 mg/ml, however CSN1S2 protein of goat yogurt intermediate effectively was only in gram negative bacteria. The weakness bacteria against inhibition activity caprine CSN1S2 protein was B. cereus (Gram positive) and S. flexneri (Gram negative). Meanwhile the strongest bacteria against inhibition activity caprine CSN1S2 protein was S. typhi (Gram negative), may cause in this bacteria has lipopolysaccharide prevent to interact with that protein as proper. CONCLUSION: This study result concluded that the caprine CSN1S2 protein has inhibition activity in opposition to pathogenic bacteria by optimal concentration 5 mg/ml in all bacteria and indicated caprine CSN1S2 protein as anti-microbial agent.