α-glucosidase inhibitors isolated from Mimosa pudica L.

The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 µg mL-1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 µg mL-1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future.

Studies on water quality and pathogenic bacteria in coastal water Langkawi, Malaysia.

A study on physico-chemical parameters and pathogenic bacterial community was carried out at the coastal waters of Pulau Tuba island, Langkawi. The physico-chemical parameters such as temperature (27.43-28.88 degrees C), dissolved oxygen (3.79-6.49 mg l(-1)), pH (7.72-8.20), salinity (33.10-33.96 ppt), total dissolved solids (32.27-32.77 g l(-1)) and specific conductivity (49.83-51.63 mS cm(-1)) were observed. Station 3 and station 4 showed highest amount of nitrates (26.93 and 14.61 microg at N l(-1)) than station 1 (2.04 microg at N l(-1)) and station 2 (4.18 microg at N l(-1)). The highest concentration (12.4 +/- microg l(-1)) of chlorophyll a was observed in station 4 in October 2005. High phosphorus content (561 microg P l(-1)) was found in the station 2. Thirteen bacterial isolates were successfully identified using API 20E system. The highest amount of bacteria was observed at Station 4 (3400 CFU ml(-1)) and the lowest numberwas at Station 2 (890 CFU ml(-1)). Out of identified 13 Gram-negative bacterial isolates dominant species were Aeromonas hydrophila, Klebsiella oxytoca, Pseudomonas baumannii, Vibrio vulnificus, Proteus mirabilis, Providencia alcalifaciens and Serratia liquefaciens. Apart from this, oil biodegrading Pseudomonas putida were also identified. The study reveals the existing status of water quality is still conducive and the reasonably diverse with Gram-negative bacteria along the Pulau Tuba Langkawi.

Present status and approaches for the sustainable development of community based fish culture in seasonal floodplains of Bangladesh.

Coordination among the different stakeholders at policy planning, implementation and target beneficiary level, particularly among the agencies responsible for development and management of water resources, agriculture and fisheries, is essential for overall sustainable development. Stocking of larger fingerlings at suitable stocking densities of endemic (rohu, catla, mrigal) and exotic (silver carp, bighead carp, common carp/mirror carp) species should be stocked at varying proportion. Floodplain fish production depends only on the natural fertility of the water bodies. Technological interventions should include the installation of low cost bamboo fencing at water inlet and outlet points and setting of ring culverts for maintaining suitable levels of water for fish culture without hampering the production of rice and other crops in the intervention areas, selective stocking with native and exotic carps, restricted fishing for certain period of time and guarding. It is expected to exert positive influences in enhancing the standing crop and biodiversity of non-stocked species of fishes in the intervention seasonal floodplain. Entry of fish larvae, hatchlings and young fry of wild non-stocked fishes into the seasonal floodplains because of large fence spacing (approximately 1.0 cm), could restrict fishing for certain period, undisturbed habitat and guarding could contribute to higher productivity and enhancement of fish biodiversity in the seasonal floodplains. Proper motivation and effective cooperation of the beneficiaries are extremely important to culture fish in the seasonal floodplains under community based management system. Institutional support and constant vigilance from the Department of Fisheries (DoF) and local administrations are indispensable to ensure the sustainability of fish culture initiatives in the seasonal floodplains. Active participation and involvement of the local community people in all stages of fish culture operation beginning from selection of floodplains, formation of floodplain management committee, planning of fish culture activities, exercise of technical intervention, selective stocking with large fingerlings, guarding, monitoring and supervision, adopting harvesting strategies, marketing and distribution of benefits are extremely essential to ensure sustainability of the program. Mutual trust, sense of respect and good working relationship among the committee members are the basic social elements required for the success of community based fish culture initiatives.

Impact of exotic carps in the polyculture with indigenous carps: competition for food.

The fingerlings of indigenous carps such as catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala) with exotic carps such as silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis) and mirror carp (Cyprinus carpio) were cultured together in a fish pond at Bangladesh Agricultural University, Mymensingh, in order to determine the food electivity, dietary overlap and food competition among indigenous major carps and exotic carps. Phytoplankton (Chlorophyceae, Cyanophyceae), zooplankton (rotifers) were the dominant groups in the cultured pond. Chlorophyceae was dominant in the diet of rohu. Chlorophyceae and rotifers were the preferred food of catla. Mrigal preferred phytoplankton than zooplankton. Rohu showed positive electivity for zooplankton. Silver carp consumed large quantity of phytoplankton and also preferred rotifers. Chlorophyceae was the dominant food group in the diet of bighead. Mirror carp also preferred plant food organisms dominated by Chlorophyceae. Bighead had positive trends towards phytoplankton. Both mrigal and mirror carp had positive electivity towards phytoplankton. The higher level of dietary overlap occurred between rohu and silver carp followed by between rohu and bighead carp and between catla and silver carp. The lowest level of dietary overlaps occurred between rohu and mirror carp.

Diversity and distribution of fishes in tropical estuary Kuantan, Pahang, Malaysia.

A study on diversity and distribution of fish communities and water qualities were carried out from January 2009 to December 2010 to cover monsoon and non-monsoon at Kuantan estuary, Pahang, Malaysia. A total of 19 species of primary marine fish belong to 12 families were recorded. Out of 311 individuals the fish fauna was dominated by Ariidae followed by Lutjanidae and Lactaridae. As such Ariidae contributes 50% of the fish caught in the study area and its diversity index (H') was 0.97. A The Ariidae family consist of four (4) species; Arius maculatus, Arius sumatranus, Arius tenuispinis and Arius thalassinus. The Ariidae family can be found in all stations as they are euryhaline (highly tolerant to salinity) and this fish family are known to be a hardy estuarine catfish. Among all species in family Ariidae, Arius thalassinus was the most dominant (23%) among all species. As such collected species showed highest species diversity (0.34) followed by Arius tenuispinis (0.25) compared to other species. Arius tenuispinis alone contributed 11.90% among the samples caught from all stations. The fishes were caught and recorded highest in September-December. Pseudorhombus quinque ocellatus, Nibea soldado, Sardinella fimbriata, Toxotes jaculatrix, Dasyatis ushiei, Setipinna taty were the least dominant in the Kuantan estuary with 9.33% of total abundance. Physico-temperatures, such as temperature (22.03-30 degrees C), Conductivity (10.342.43 mS cm(-1)), TDS (0.06-26.34 mg L(-1)), salinity (0.05-29.09 ppt), DO (6.37-8.38 mg L(-1)), pH (4.97-8.03), Chl a (0.01-1.33 microg L(-1)), nitrite (0.01-0.08 mg L(-1)), nitrate (0.60-0.88 mg L(-1)), phosphate (0.24-0.40 mg L(-1)). Nevertheless, the study envisages that the water quality and fish diversity are still conducive in the Kuantan estuary. The fish diversity of Pahang estuary was high monsoon compared to non-monsoons. The station 4 (LKIM fishing boat jetty and adjacent Hospital Kuantan) is the most polluted area due to the presence of several outskirts could be alarming for the sustainable development of fish and other aquatic organisms in Kuantan estuary in the long run.

Length-weight relationship of Mugil cephalus (Linnaeus 1758) in Vellar estuary, southeast coast of India.

A detailed study on the length weight relationship of Mugil cephalus in Vellar estuary was conducted between January 2004 and December 2005. Statistical tests such as regression coefficient 'b' and 'a' tests were performed to compare the b values of males and females from the hypothetical value of 3. The b value of male (2.7658) differed significantly from the hypothetical value of 3 (t = -2.8586 < 0.05), the b value of female (2.8586) did not differ significantly from the hypothetical value (t = -1.0158 > 0.05). Values of both males and females were less than 3 which proved the negative allometry growth pattern.

Occurrence of Plesiomonas shigelloides in cultured red hybrid tilapia (Oreochromis niloticus) from tropical rivers, east coast Malaysia.

A total of 182 isolates of Plesiomonas shigelloides were identified from 40 healthy red hybrid tilapia, Oreochromis niloticus cultured at two important rivers in Terengganu, Malaysia namely Como River and Terengganu River from east coast Malaysia. P. shigelloides count in Digestive Tract Content (DTC) and Muscle (MUS) of red hybrid tilapia cultured at Terengganu River was 1000-fold higher than Como River. Antibiotic susceptibility test was also performed on Plesiomonas shigelloides isolates. The incidence of antibiotic resistance was higher in Plesiomonas shigelloides isolated from red hybrid tilapia cultured at Terengganu River compared to Como river. Thus, the findings of the study indicate that P. shigelloides from tilapia muscle and an intestine could be an alarming for serious public health risk to consumers.

Determination of some heavy metal concentrations in razor clam (Solen brevis) from Tanjung Lumpur coastal waters, Pahang, Malaysia.

An effort to analyze selected heavy metal accumulation by the razor clam (Solen brevis) from Tanjung Lumpur was conducted on January to April 2010. A total of fifty individuals of Razor clam Solen brevis were sampled and metals such as Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), Lead (Pb) and Cadmium (Cd) Concentrations were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Among the metals Fe occurred in elevated concentration in the soft tissue of razor clam followed by Zn. Cd was found to be in least concentration in the sample. Mean concentration of Fe, Zn, Mn, Cu, Cd and Pb in the soft tissue were 415.2 +/- 56.52, 87.74 +/- 11.85, 18.71 +/- 2.10, 8.64 +/- 1.75, 0.67 +/- 0.29 and 1.61 +/- 0.45 microg g(-1) dw, respectively indicating that the bioaccumulation of essential metals in the soft tissue was greater than the non essential heavy metals. Metal accumulation in the soft tissue of razor clam followed Fe > Zn > Mn > Cu > Pb > Cd order in present study. The observed concentration of acute toxicity of metals in Solen brevis (Family: Solenidae) from Tanjung Lumpur Coastal waters was lower than the permissible limit recommended by National and international standards proved that this species could be utilized for human consumption.

Optimization of lignin peroxidase production and stability by Phanerochaete chrysosporium using sewage-treatment-plant sludge as substrate in a stirred-tank bioreactor.

A laboratory-scale study was carried out to produce lignin peroxidase (ligninase) by white rot fungus (Phanerochaete chrysosporium) using sewage-treatment-plant (STP) sludge as the major substrate. The optimization was done using full-factorial design (FFD) with agitation and aeration as the two parameters. Nine experiments indicated by the FFD were fermented in a stirred-tank bioreactor for 3 days. A second-order quadratic model was developed using the regression analysis of the experimental results with the linear, quadratic, and interaction effects of the parameters. Analysis of variance (ANOVA) showed a high coefficient of determination (R (2)) value of 0.972, thus indicating a satisfactory fit of the quadratic model with the experimental data. Using statistical analysis, the optimum aeration and agitation rates were determined to be 2.0 vvm and 200 rpm, respectively, with a maximum activity of 225 U l(-1) in the first 3 days of fermentation. The validation experiment showed the maximum activity of lignin peroxidase was 744 U l(-1) after 5 days of fermentation. The results for the tests of the stability of lignin peroxidase showed that the activity was more than 80% of the maximum for the first 12 h of incubation at an optimum pH of 5 and temperature of 55 degrees C.

Optimization of decolorization of methylene blue by lignin peroxidase enzyme produced from sewage sludge with Phanerocheate chrysosporium.

Optimization of decolorization of methylene blue (MB) dye by lignin peroxidase (LiP) enzyme produced by white-rot fungus Phanerochaete chrysosporium using sewage treatment plant (STP) sludge as a major substrate was carried out in the laboratory. Optimization by the one-factor-at-a-time (OFAT) and statistical approach was carried out to determine the process conditions on optimum decolorization of MB dye using LiP enzyme in static mode. The OFAT method indicated that the optimum conditions for decolorization of MB dye (removal: 14-40%) was at temperature 55 degrees C, pH 5.0 with hydrogen peroxide (H(2)O(2)) concentration 4.0mM, MB dye concentration 20mg/L and LiP activity 0.487U/ml. The addition of veratryl alcohol to the reaction mixtures did not contribute any further increases in decolorization. The initial concentration of MB and the activity of LiP enzyme were further optimized using response surface methodology (RSM). The contour and surface plots suggested that the optimum initial concentration of MB and LiP activity predicted were 15mg/L and 0.687U/ml, respectively for the removal of 65%. The validation of the model showed that the decolorization process gave the higher removal of 90% in agitation mode compared to the static mode with 65% for 60min of incubation time by LiP enzyme.

Accumulation of lead and copper in Rhizophora apiculata from Setiu mangrove forest, Terengganu, Malaysia.

The accumulative partitioning of Pb and Cu in the Rhizophora apiculata was studied randomly in the Setiu mangrove forest, Terengganu. Samples of leaves, barks and roots were collected randomly from the selected studied species. Sediments between the roots of the sampled mangrove plants were also collected. The results from analysis for Rhizophora apiculata shows that the concentration of Pb and Cu were accumulated higher in root tissue compared to bark and leaf tissue but lower than surrounding sediment level. The average concentration of Cu for Rhizophora apiculata in leaf, bark, root and sediment was 2.73, 3.94, 5.21 and 9.42 mg I(-1), respectively. Meanwhile, the average concentration of Pb in leaf, bark, root and sediment was 1.43, 1.38, 2.05 and 11.66 mg l(-1), respectively. Results of concentration factors (CF) show that the overall the concentration of Pb and Cu were accumulated much higher in roots system of Rhizophora apiculata.