NISCAIR Online Periodicals Repository Collection: IJMS Vol.40(4) [August 2011]

Ecological study of Phytoplankton from Dahanu creek- west coast of India.

Title: Ecological study of Phytoplankton from Dahanu creek- west coast of India.

Authors: Kadam, S.S.; Tiwari, L.R.

Abstract: Diversity of phytoplankton and water quality of Dahanu creek was studied during November 2008 and October 2009. Physicochemical parameters indicated variations in depth, pH, temperature. DO, BOD, salinity, nitrite, nitrate, ammonium nitrate, phosphate etc. Total 52 genera of phytoplankton were observed during the study period comprising diatoms, dinoflagellates and other algae. Coscinodicuss, Rhizosolenia, Biddulphia, Melosera, Bacillaria, Isthmia, and Gyrosigma were dominated among the phytoplankton community. Diversity index of phytoplankton ranged from 2.61 to 6.37. Dahanu creek maintained fairly high concentration of chlorophyll a, ranging between 0.96 to 7.65 (average 3.30). Maximum value of chlorophyll a was recorded at stn.1 from the bottom water during June 2009 which coincided with the highest cell count of phytoplankton total 758 phytoplankton recorded for that station. This was also associated the boom of coscinodicuss.There was gradual increases in chlorophyll a from creek area. Distribution of phaeophytin ranged from 0.65 to 4.49 (average 1.94) and it was comparable with chlorophyll a. However Station 1-3 maintained higher value of chlorophyll a than the phaeophytin while the area of station 4-5 showed low concentration of chlorophyll a and phaeophytin. Dahanu creek consists of rich and divers phytoplankton community.

Page(s): 593-597

Influence of abiotic environmental factors on the abundance and distribution of Vibrio species in coastal waters of Kerala, India

Title: Influence of abiotic environmental factors on the abundance and distribution of Vibrio species in coastal waters of Kerala, India

Authors: Prasanthan, V.; Udayakumar, P.; Sarathkumar; Ouseph, P.P.

Abstract: Quantification of Vibrio spp. and abiotic environmental factors on the proliferation and longevity of V. parahaemolyticus and V. cholerae was studied. Water samples were collected onboard CRV Sagar Purvi from Veli, Neendakara, Kochi, Calicut and Kasaragod along the Kerala coast for hydrological and microbiological parameters. Pearson correlation and regression analysis were done for evaluating the relationship between abiotic environmental factors and abundance of Vibrio spp. Hydrological and microbiological variations are greatly observed at nearshore transect of all stations. Significant correlation was observed between V. cholerae and nutrients and negative correlation with pH, dissolved oxygen and salinity. The population of V. parahaemolyticus showed an inverse correlation with dissolved oxygen. pH, salinity and nutrients and these factors were responsible for the incidence and abundance of Vibrio cholerae and Vibrio parahaemolyticus. The proliferation and survivality of V.parahaemolyticus in marine waters is independent to hydrological variables while that of V.cholerae is determined by certain abiotic factors.

Page(s): 587-592

Isolation and enumeration of bacterial flora in false trevally, Lactarius lactarius of Karwar, central west coast of India.

Title: Isolation and enumeration of bacterial flora in false trevally, Lactarius lactarius of Karwar, central west coast of India.

Authors: Hakkimane, Shreedevi S.; Rathod, J.L.

Abstract: Significant amount of fish catch at Karwar fishing centre is brought from mechanized and non-mechanized means of fishing. During present investigation, quantitative and qualitative estimation of bacterial flora present in gills, stomach and intestine of fresh false trevally, Lactarius lactarius were performed and bacteria were identified to genus level. Mean total plate counts on Nutrient Agar (NA) and Zobell Marine Agar (ZMA) media was found to be 5.45X10⁵ and 1.64X10⁶ cfu/g in gills, in stomach 1.5X10⁴ and 5.5X10⁴ cfu/g, in intestine 4.16X10⁴ and 2.82X10⁵ cfu/g respectively. Gram negative rod shaped bacteria dominated (75.2%) the populations. Among gram positives, Micrococcus spp. and Bacillus spp. were dominant, while among gram negatives, Vibrio spp. occurred in more numbers followed by Pseudomonas spp., Flavobacterium spp., Acinetobacter spp., Alcaligens spp. and Aeromonas spp. where as Sarcina spp. (9.09%) was found only in stomach and Arthrobacter spp. (4.61%) was found only in gills.

Page(s): 583-586

Potential bioactive compound from marine actinomycetes against biofouling bacteria

Title: Potential bioactive compound from marine actinomycetes against biofouling bacteria

Authors: Bavya, M; Mohanapriya, P; Pazhanimurugan, R; Balagurunathan, R

Abstract: In the present study, 25 bacterial isolates were recovered from fouling samples collected from Parangipettai coastal area. Based on their adherence property, three isolates were characterized and identified as Bacillus sp. (BB11), Serratia sp. (BB13) and Alteromonas sp. (BB14). Six out of 20 actinomycete extracts showed inhibition of biofouling bacteria in disc diffusion method. Strain R1 extract showed maximum inhibition against all the biofouling bacteria tested. Culture filtrate and ethyl acetate extract from strain R1 showed 13-15 mm inhibition against biofouling bacteria. Reduction in biofilm formation was also observed in cover slip method. Active antifouling compound was purified using TLC and detected by bioautography. Based on chemical screening, the active compound was tentatively identified as sugar containing molecule. potential actinomycete strain R1 was characterized and identified as Streptomyces filamentosus (R1). Present study concluded that the marine actinomycete, Streptomyces filamentosus (R1) will be a potential source for the development of eco-friendly antifouling compounds. This will be a better alternative to the pollution causing synthetic antifoulants.

Page(s): 578-582