Sustainable potential analysis of Indian mackerel (rastrelliger kanagurta) resource in East Coast waters of Aceh Province

Fishery of the Indian mackerel Rastrelliger kanagurta (Cuvier, 1816) from Tuticorin was studied for the period 2011-2014. Indian mackerel formed fishery round the year in Tuticorin with peak during June to November in trawl and October to December in gillnet. The annual catch varied from 1650 to 5101 t (average 2968 t) in gillnet and from 815 to 1716 t (average 1231 t) in trawl. Total length (TL) of the fishes ranged from 10 to 30.5 cm. Length-weight relationship estimated was W = 0.0038777*L3.3 (r2 = 0.99, n = 535, L=TL in cm, W in g). The fishes were found to be continuous spawners with peak spawning during January to August and November. The von Bertalanffy growth equation derived was Lt = 31.2 [1-e -1.3(t+t0)]. The species attained TL of 22.7 cm in 12 months and 28.9 cm by the end of second year. Longevity estimated was 2.3 years, Phi-prime index (ᴓ) was 7.143, while Z and M were 4.36 and 2.132 respectively. Thompson and Bell model showed continuous increase of yield even after considerable rise in F-factor. Spawning stock biomass (SSB) was 79% at an f-factor of 3.5. F0.1 using Beverton and Holt Y/R model was 3.4 whereas the present F was 2.23 indicating that the current level of fishing is not affecting the stock adversely.

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Biomedical applications of fish gut associated Streptomyces maritimus IM20 isolated from Rastrelliger kanagurta (Indian mackerel)

Research Journal of Biotechnology ◽

10.25303/1610rjbt120130 ◽

2021 ◽

Vol 16 (10) ◽

pp. 120-130

Author(s):

Angamuthu Vignesh ◽

Venugopal Gopikrishnan ◽

Sivaraj Anbarasu ◽

Manikkam Radhakrishnan ◽

Joseph Jerrine

Keyword(s):

Ethyl Acetate ◽

Ethyl Acetate Extract ◽

Radical Scavenging ◽

Bioactive Metabolites ◽

Molecular Characteristics ◽

Inhibition Assay ◽

Indian Mackerel ◽

Fish Gut ◽

Rastrelliger Kanagurta

The biomedical potential of fish gut-associated actinobacteria isolated from the marine fish Rastrelliger kanagurta (Indian mackerel) was investigated. The actinobacterial strain IM20 was isolated from the fish gut by using Kusters agar medium prepared with 50% sea water. Based on their phenotypic and molecular characteristics, strain IM20 was identified as Streptomyces maritimus. The bioactive metabolites produced from the strain IM20 by agar surface fermentation and ethyl acetate extraction were tested for in vitro antimicrobial, antiquorum sensing , anti-biofilm, anti TB, anti-oxidant and anti-cancer activity. The MIC value of ethyl acetate extract (EAE) of IM20 was found to be 16 μg ml−1 against S. aureus and E. coli. In quorum sensing inhibition assay, the extract showed violacein inhibition upto 87% at 512 μg ml−1 concentration when tested by pigment inhibition assay using C. violaceum MTCC 2656. The results of in vitro assays revealed that the ethyl acetate extract of IM-20 (EAE-IM20) showed 75%, 83% and 72% inhibition against Mycobacterium tuberculosis H37Rv, M. tuberculosis (SHRE sensitive) and multi drug resistant (MDR) M tuberculosis respectively at 500 μg ml−1 concentration. In DPPH assay, 71% radical scavenging activity was exhibited by the EAE-IM20 at 250 μg ml−1. In MTT assay, EAEIM20 exhibited 74.29±2.01% inhibition on breast cancer cell line MCF7 (250 μg ml−1). This study broadly determines that the fish associated actinobacteria is a prolific place for diverse multifunctional bioactive compounds for the development of medically important unique drugs.

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