Heavy Metals Concentration in Fish Mugil cephalus from Machilipatnam Coast and Possible Health Risks to Fish Consumers.

Heavy metals are dangerous to aquatic organisms and it can be bioaccumulated in the food chain leading to diseases in humans. Cumulative effects of metals or chronic poisoning may occur as a result of long term expore even to low concentrations. The accumulation of heavy metals conditions depending upon the species, environmental conditions and inhibitory processes. Considering the human health risk due to the consumption of fish, the concentration of heavy metals (Zn, Pb, Mn, Cu, Cr and Hg) are investigated in fish samples collected from the Machilipatnam coast. The fish was examined for metal constituents are the basis on the human nutrition in the study area. These metal concentrations were exceeding the limits set by the world health organization (WHO). The study provides an insight into the potential impact of increased levels of metals in the environmental as well as estimated of the contaminated of fish tissues with metals.

Studies on influence of natural biowastes on cellulose production by Aspergillus niger.

The objective of this study was to determine the influence of natural biowaste substrates such as banana peel powder and coir powder at varying environmental parameters of pH (4-9) and temperature (20-50oC) on the cellulase enzyme production by Aspergillus niger. The cellulase enzyme production was analyzed by measuring the amount of glucose liberated in IU ml-1 by using the dinitrosalicylic acid assay method. The substrates were pretreated with 1% NaOH (alkaline treatment) and autoclaved. The maximum activity of the enzyme was assayed at varying pH with temperatures being constant and varying temperatures with pH being constant. The highest activity of the enzyme at varying pH was recorded at pH 6 for banana peel powder (0.068 + 0.002 IU ml-1) and coir powder (0.049 ± 0.002 IU ml-1) and the maximum activity of the enzyme at varying temperature was recorded at 35oC for both banana peel powder (0.072 ±0.001 IU ml-1) and coir powder (0.046 ±0.003 IU ml-1). At varying temperatures and pH the high level of enzyme production was obtained at 35oC and pH 6 by using both the substrates, respectively. However among the two substrates used for the production of cellulases by Aspergillus niger banana peel powder showed maximum enzymatic activity than coir powder as substrate.