Based on the findings, the present study concluded that, there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.

Ornamental goldfish Carassius auratus were treated with whole cell (WC), extracellular product (ECP), outer membrane protein (OMP) and biofilm (BF) vaccines developed from the virulent Aeromonas hydrophila (AHV1; GenBank HQ331525.1) with and without the immunoadjuvant Asparagus racemosus. On various days post-vaccination (dpv), the treated fish were challenged with virulent A. hydrophila. These fish were monitored for survival, growth, specific bacterial reduction, and biochemical, haematological and immunological parameters. C. auratus attained 100% mortality within 7 d in non-vaccinated groups, whereas the vaccines helped to significantly (p ≤ 0.001) increase survival after 25 and 50 dpv. The vaccines with immunoadjuvant (ECP 2 , OMP 2 and BF 2 treatments) helped to reduce the Aeromonas load after the challenge, and serum albumin, globulin and protein levels were significantly (p < 0.01) improved in the OMP 2 -and BF 2 -treated groups. Haemoglobin and red blood cell counts were also significantly improved (p < 0.05) in the vaccinated groups compared to the control group. Additionally, haemagglutination occurred at the 1:12 dilution level in the vaccine plus immunoadjuvant-treated groups. Supplementing the vaccines with immunoadjuvant helped to improve phagocytosis to 54.07%, serum bactericidal activity to 14.6% and the albumin:globulin ratio to 7.6% in BF 2 after 50 dpv. Its positive effect significantly (p < 0.05) increased in vaccinated groups compared to controls. Based on the results, especially with the OMP and BF vaccines, the immunoadjuvant A. racemosus helped to improve the efficiency of the vaccines. This approach will aid in the development of more efficient vaccines against bacterial infections affecting the aquaculture industry. KEY WORDS:Ornamental fish · Biofilm · Outer membrane protein · OMP · Herbal immunoadjuvants Resale or republication not permitted without written consent of the publisher

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Bacillus cereus TC-1 was isolated from condenser pond of manmade solar salt pan Thamaraikulam, Tamilnadu, India effectively suppressed the shrimp bacterial pathogens Vibrio harveyi, V. parahaemolyticus, V. anguillarum, V. alginolyticus and V. vulnificus by in vitro antagonistic assay of 9 to 15 mm of zone of inhibition. Phylogenetic analysis revealed that, B. cereus TC-1 was highly similar that the B. thuringiensis strain (100%) and other Bacillus sp. Their optimum growth between at the range of 4 to 6% of NaCl in the growth media and significantly (P<0.05) high alkaline protease production (170.85 U/ml) was observed in the NaCl of 6 %. Based on the antagonistic activity of the B. cereus TC-1 against the shrimp pathogens and its antimicrobial factors, it may be used as probiotics and developing novel antimicrobial bioactive substances against aquatic pathogens.