Heterotrophic bacterial flora of Pmonadon from an apparently healthy hatchery system as well as a pool with heavy mortality were isolated and studied. In the
healthy systems comparatively higher generic diversity with Pseudomonas, Acinetobacter, Bacillus, Micrococcus, members of the family Enterobacteriaceae
and coryneform group in the diminishing order of dominance was recorded. Meanwhile from the moribund larvae and rearing water Aeromonas and Pseudomonas
could be isolated in almost equal proportions. Strikingly, Aeromonas could not be isolated from the apparently healthy larval rearing system and its exclusive
occurrence in the sick culture system in comparatively higher percentage suggested its possible role in the mortality. They were found to be highly halophilic
exhibiting growth at 10% NaCl. On testing their sensitivity to twenty antibiotics, four of them (Streptomycin, Gentamycin, Methamine mandelate and
Cloramphenicol) were found to be effective on all the isolates of Aeromonas and Pseudomonas suggesting their possible application in the hatchery system in
times of emergency. While doing so, Streptomycin would do comparatively better than the others as the minimum inhibitory dose required was comparatively
lower (200ppm) within a period of 24 hours
Optical fiber based laser induced fluorescence (LIF)
measurements were carried out using Rhodamine B to analyze
two different species of bacteria , a Gram-positive bacteria
namely Bacillus smithii , and fibrin alginolvticus, a Gram-
negative bacteria . The fiber sensor was clearly able to distinguish
between the two species of bacteria . Quenching effect of the dye
Rhodamine B by Bacillus smithii was observed . The effect of dye
on the samples was also studied in detail.
Sarita,G Bhat; Jasmin, C; Sreeja, Chellappan; Rajeev, K Sukumaran; Elyas, K K; Chandrasekaran, M(Springer, January 10, 2010)
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Abstract:
An alkaline protease gene (Eap) was isolated
for the first time from a marine fungus, Engyodontium
album. Eap consists of an open reading frame of 1,161 bp
encoding a prepropeptide consisting of 387 amino acids
with a calculated molecular mass of 40.923 kDa. Homology
comparison of the deduced amino acid sequence of
Eap with other known proteins indicated that Eap encode
an extracellular protease that belongs to the subtilase
family of serine protease (Family S8). A comparative
homology model of the Engyodontium album protease
(EAP) was developed using the crystal structure of proteinase
K. The model revealed that EAP has broad substrate
specificity similar to Proteinase K with preference for
bulky hydrophobic residues at P1 and P4. Also, EAP is
suggested to have two disulfide bonds and more than two
Ca2? binding sites in its 3D structure; both of which are
assumed to contribute to the thermostable nature of the
protein.
Description:
World J Microbiol Biotechnol (2010) 26:1269–1279
DOI 10.1007/s11274-009-0298-6
An experiment was designed to assess the occurrence of multiple antibiotic resistances in
Vibrio sp from different (brackish and marine) environments. Water samples front nine marine landing
sites and two coastal inland aquaculture farms were screened for the Vibrio spp and assessed their
resistance to twenty-two different antibiotics, which arc commonly encountered in the aquatic
ecosystem. Tissue samples (shrimp, mussel and sepia) were tested from the sampling site with highest
antibiotic resistance. Of' the total 119 Vibrio isolates, 16. 8% were susceptible to all antibiotics. Of the
resistant (83.19%) Vibrio strains, 30.3% were resistant against three antibiotics, 55.5% were resistant
against 4-10 antibiotics, 14.14% were resistant against more than 10 antibiotics and 54% have shown
multiple antibiotics resistance (MAR). Antibiotic resistance index was higher in Coastal 3, 6, Aqua
farm 2 in isolates from water samples and all the tissues tested. Interestingly, incidence of antibiotic
resistance in isolates from water samples was comparatively lower in aquaculture farms than that
observed in coastal areas. Highest incidence of antibiotic resistance was evident against Amoxycillin,
Ampicillin, Carbencillin and Cefuroxime followed by Rilanipicin and Streptomycin and lowest against
Chloramphenicol, Tetracycline, Chlortetracycline, Furazolidone, Nalidixic acid, Gentamycin
Sulphafurazole, Trimcthoprinr, Neomycin and Amikacin irrespective of the sampling sites. Results
from various tissue samples collected from the sites of highest antibiotic resistance indicated that
antibiotic resistance Vibrio spp collected from fish and tissue samples were higher than that of water
samples. Overall results indicated that persistent use of antibiotics against diseases in human beings
and other life forms may pollute the aquatic system and their impact on developing antibiotic resistant
Vibrio sp may be a serious threat in addition to the use of antibiotics in aquaculture farms.