Comparative Study on the in vitro Antibacterial Efficacy of Aqueous and Methanolic Extracts of Quercus infectoria Gall`s Against Cellulosimicrobium cellulans

The in vitro antibacterial efficacy of aqueous and methanolic extract of Quercus infectoria Olivier (Fagaceae) galls was tested against Cellulosimicrobium cellulans using extract concentration ranging from 0.25 to 4 mg mL-1. Both types of extract showed significant inhibition of C. cellulans growth with strong correlation between extract concentrations and degrees of antibacterial activity for concentrations ranging from 0.5 to 4 mg mL-1. Although, slight reduction of average diameter of inhibition zones after 24 h of incubation for aqueous extract (0.96 ± 0.148 cm) compared to methanolic extract (1.00 ± 0.182 cm), both extracts still attained the MIC value beginning at a concentration of 0.5 mg mL-1 but established higher concentration for the MBC at 2 mg mL-1. The antibacterial activity of methanolic extract was also significantly affected by the temperature with an optimum inhibition zone being obtained at 30 °C (1.38 ± 0.05 cm) and this was reduced to approximately 20% at temperatures of above 50 °C

Catch composition of a set bag net (SBN) used for Acetes trapping in the estuarine waters of Kedah, Peninsular Malaysia.

A study was conducted for a 12-month period, from June 2008 to May 2009 based on the catch data to determine the catch composition of Set Bag Net (SBN) that is a type of fishing net laid down to catch Acetes shrimps that move along the estuary of Merbok River in the state of Kedah, Peninsular Malaysia. Bag net is a static traditional gear with a cod end mesh size measuring 0.5 cm. The results showed that total catches of the bag net over a year period were constituted of three major catch groups viz. Acetes shrimps (89%), juvenile fishes (9%) and other non-Acetes shrimps (2%). The annual mean percentage composition of sergestid shrimps comprised of A. japonicus, A. vulgaris and A. indicus were found to be 89, 7 and 4%, respectively. The gear is very selective and besides Acetes there was also a small proportion of fish juvenile being caught. Seven species of juvenile fishes were recorded throughout the catch period however; their mean total abundance was very low (9%). Penaeid shrimp was the only group of non-Acetes shrimp been recorded. Based on the analyzed catch composition data, it could be concluded that SBN is Acetes-selective and not causing significant great damage to the juvenile fish population inhabiting the study area

Identification of phenanthrene and pyrene degrading bacteria from used engine oil contaminated soil

The purpose of the study was to identify effective bacteria that degrade phenanthrene and pyrene from used engine oil contaminated soil. A total of 93 bacterial isolates were obtained and their degradations were determined. Based on culture-depended technique and tested for in vitro phenanthrene and pyrene degradations using spray plate technique and colorimetric assay with 2,6-dichloroindophenol (DCPIP). Fifty three isolates shows evidence of 5 g/l phenanthrene degradation within 72 hours in spray plate technique. Further 23 isolates were selected from 53 isolates after the colorimetric screening. Biodegradation study shows two isolates named MM045 and MM087 with 75.2% and 80.2% degradations for 500 mg/l phenanthrene and also 54.3% and 59.7% of 250 mg/l pyrene degradations within 24 hours respectively. These isolates were identified as Cronobacter sakazakii strain MM045 (Accession number: KT933253) and Enterobacter specie strain MM087 (Accession number: KT933254) using 16S rRNA gene sequencing and neighbour joining tree analyses. The identified isolates were proven to be fast effective in degrading high concentrations of phenanthrene and pyrene as their sole carbon and energy sources

Effective phenanthrene and pyrene biodegradation using Enterobacter sp. MM087 (KT933254) isolated from used engine oil contaminated soil

Phenanthrene and pyrene are low and high molecular weights polycyclic aromatic hydrocarbons (pahs) being classified as priority organic pollutants in the environment. this study was aimed to optimizing pahs biodegradation conditions and then identifying intermediate metabolites using effective enterobacter sp. mm087 (kt933254). biodegradation quantitative experiments were carried out using colorimetric assay and the intermediate metabolites were identified based on gas chromatography mass spectrophotometer (gc–ms). enterobacter sp. mm087 initially degraded 80.2% phenanthrene (500 mg/l) and 59.7% pyrene (250 mg/l) within 24 h. further enhancement of the culture conditions involving agitation, temperature, ph, inoculums volume and salinity was carried out using response surface methodology (rsm) based on central composite design (ccd). the ccd optimizations allowed the interactions among the culture conditions which eventually resulted in 100% degradation in each of the phenanthrene and pyrene thereby released non-hazardous metabolites. correlation between the predicted and actual results further validated the ccd optimization. the phenanthrene metabolites identified were 3,4-dihydroxyphenathrene, phthalate, pyruvic acid and acetic acid. pyrene metabolites identified involved pyrene cis-4,5-dihydrodiol, 3,4-dihydroxyphenathrene, phthalate, pyruvic acid, acetic acid and formic acid. the biodegradation experiments were finally validated using numerical optimizations. enterobacter sp. mm087 was found to rapidly degrade 500 mg/l phenanthrene and 250 mg/L pyrene within 24 h which makes it a very efficient and rapid PAHs degrader

Ecology of aquatic worms in the Langat River, Selangor Peninsular Malaysia.

A study was conducted to determine the diversity and density of aquatic worms in Langat River, Selangor, Peninsular Malaysia and its relationship with the physicochemical parameters that influence the distribution of the worms. The three annelid species found were the oligochaetes, Limnodrilus sp. and Dero sp. and the polychaetes from family Nereididae. The density of different taxonomic groups differed among the sites with all the aquatic worms showing correlation with the physicochemical parameters studied (except conductivity). Dero sp., Limnodrilus sp. and Nereididae showed negative correlation with dissolved oxygen. The aquatic worms showed positive correlation with temperature and organic matter content. Dero sp. (r=0.135) showed positive correlation with pH but both Limnodrilus sp. (r=-0.727) and Nereididae (r=-0.420) showed a negative correlation

Evaluation of nutrients released from phosphorus-enriched empty oil palm fruit bunches as growing media using Setaria splendida.

The use of oil palm empty fruit bunch, an agricultural waste from oil palm plantations, as a feeding material for earthworms during composting provides an alternative source of nutrients for plants. Information regarding the ability of earthworms in processing phosphorus-enriched empty oil palm fruit bunch and their effects on plants is still lacking. The objective of this study was to compare the effects of phosphorus-enriched empty oil palm fruit bunches applied as fresh, composted or vermicomposted media in supplying nutrients on a test crop, Setaria splendida L., grass planted on Bungor (Typic Kandiudult) soil. The soil treated with phosphorus-enriched vermicomposted empty oil palm fruit bunch increased the grass dry matter yield significantly higher compared to that treated with composted empty oil palm fruit bunch and control. The root volume of vermicomposted- and composted- empty oil palm fruit bunches treated soil was similar but significantly greater than the control. There was significant interaction between dosage and type of growing media on cumulative N, P, K, Ca, and Mg uptake. However, these factors did not show significant influence on total N, P, Ca and Mg in the soil amended with composted oil palm empty fruit bunch at the end of the experiment. In general, phosphorus-enriched vermicompostedand phosphorus-enriched composted- empty oil palm fruit bunches treated soil resulted in a greater positive effect on growth and nutrient uptake of S. splendida, and also on the total nutrient content in soil except for total K. Total soil K in the control treatment was 242.0 mg/kg and significantly higher compared to soil treated with composted- (173 mg/kg) and vermicomposted- empty oil palm fruit bunches (167 mg/kg). The vermicomposted empty oil palm fruit bunch resulted in better growth performance of the S. splendida in comparison to composted- and fresh- empty oil palm fruit bunches due to the readily available P and other nutrients being readily available to the plants

Population fluctuation and dispersion patterns of apple snails, Pomacea spp. (Gastropoda: Ampullariidae) in a rice ecosystem

A field study was conducted for two consecutive rice-growing seasons from August, 2013 to May, 2014 to understand the population dynamics of exotic apple snails, Pomacea spp. (Ampullariidae), as affected by ambient weather and aquatic weeds. A one-acre rice field was divided into four blocks and eight samples per block were taken using a 0.5x0.5m quadrat. Collected snails were recorded as numbers of egg clutches, juveniles, adult females and males. Average rainfall, relative humidity, temperature and water pH, along with number of aquatic weeds and seedlings, were also recorded. Results confirmed the presence of only Pomacea maculata. The numbers of egg clutches, juveniles and adults were relatively high during the off-season as compared to the main-season. Meanwhile, relative humidity had a significant effect on the number of egg clutches, and rainfall affected the densities of juveniles and adults. Among the weeds, Limnocharis flava (Alismataceae) had significant effect on the densities of different snail stages. Different stages showed uniform dispersion pattern during both seasons due presumably to continuous availability of water and abundant food. Thus, results obtained could be helpful in understanding the population dynamics of P. maculata and devising appropriate management strategy

Enhancement of protease production by the optimization of Bacillus subtilis culture medium.

Aims: Traditionally, crustacean wastes have been managed by using acid and alkali which leads to major environmental issue. However, over the recent years microbial fermentation has gained its way whereby producing similar effects as chemical treatment and a higher quality product can be obtained. Extracellular protease from Bacillus subtilis was used further by optimizing its culture medium to enhance protease production. Methodology and Results: The culture media was optimized with 4 various sources; Shrimp Crab Shell Powder (SCSP), nitrogen sources, inorganic salts, and carbon sources. It was found that culture media supplemented with 9% SCSP, 3% yeast extract, 1% sodium chloride and 9% glucose augmented protease activity up to 565.80 ± 19.41 U/mL compared to the un-optimized media (170.57 ± 6.75 U/mL). By using this optimized media, the ability and efficiency of B. subtilis in a period of 6 days was investigated whereby acid treated shrimp shells (ATSS) and raw shrimp shell powder (RSSP) were used in substitution of SCSP. In a period of 6 days, the protein content in both ATSS and RSSP was found to have been removed up to 60% and 42% respectively. However deproteinization was found to be more efficient in RSSP with the ratio of tyrosine to protein remained constantly high throughout the 6 days period. Conclusion, significance and impact of study: A better, more efficient and environmental friendly method is continuously being improvised to manage shrimp wastes with the use of microbes

Efficiency of polycyclic aromatic hydrocarbons (PAHs) degrading consortium in resisting heavy metals during PAHs degradation

Polycyclic aromatic hydrocarbons (PAHs) comprised of many dangerous organic pollutants which affect human cell. The choice of phenanthrene and pyrene as model substrates was based on their classification among the most hazardous PAHs group by the US EPA where they belonged to low and high molecular weights PAHs respectively. Biodegradation of these PAHs is the best strategy that completely removes such pollutants in an environmentally friendly manner. However, the bacteria involved are challenged degradation difficulties as a result of PAHs inhibitory effects to the organisms. This research is aimed at formulating phenanthrene and pyrene degrading consortium that effectively perform best even in complex mixture with hazardous heavy metals. Different bacteria consortia were formulated using the compatibility testing and mathematical permutation approach and the best consortium selected. This selected consortium was then subjected to the degradation of both phenanthrene and pyrene separately in a combined mixture with the selected heavy metals from the inductively coupled plasma optical emission spectrophotometer (ICP-OES) analysis. Consortium composition of C. sakazakii MM045 (2%, v/v) and Enterobacter sp. MM087 (2%, v/v) were found to be much effective during phenanthrene (500 mg/L) and pyrene (250 mg/L) degradation. This consortium also resisted more than 6 mg/L each of Nickel (Ni), Cadmium (Cd), Vanadium (V) and Lead (Pb) in such complex degradation which was found to be more than the concentration in the natural habitat the consortium exists prior to isolation. Such performance makes the selected consortium to be an extremely efficient tool for the PAHs degradation application as many biodegradation agents were reported to be less effective when significant concentration of Ni, Cd, V and Pb are present

Diversity of Trichoderma species isolated from soil

Soils consist of complex mixtures of mineral, water, air, organic matter and as an ecosystem of a large number of countless microorganisms such as bacteria, fungi and nematodes. Due to the limitation on understanding of fungi biodiversity in soil, many people do not know there consists of very useful microbe that can help in suppression of plant pathogens. Trichoderma (Hypocreales, Ascomycota) is one of the microorganisms that living in all types of soil. Trichoderma species has been used as a biological control agent of phytopathogens due to its abundance and having an antagonistic property. This study will provide checklists of Trichoderma species that have been isolated from cultivated crop soils in Malaysia. The objectives of this study are to isolate and identify Trichoderma species from soil based on morphological characterization and to calculate diversity of Trichoderma species based on Shannon-Wiener Index. Soil samples from each cultivated agricultural crops were collected in three spots in 17 locations around Malaysia. Isolation of Trichoderma was completed using soil dilution technique to obtain a pure single colony-forming unit (CFU). A total of 253 of Trichoderma isolates were successfully isolated from rhizosphere of different crops. All isolates were tentatively identified into six species such as T. harzianum (114 isolates), T. asperellum (65 isolates), T. hamatum (22 isolates), T. viride (26 isolates),T. koningii (20 isolates) and T. virens (6 isolates).The differences between species were characterized based on their colony features, pigmentation on potato dextrose agar (PDA) and the branching of conidiophores. The diversity index of Trichoderma species found in the Malaysia soil was 1.43 and T. harzianum was dominated. Due to diverse species of Trichoderma found in Malaysia, it will increase the opportunity in selection for biological control agent of plant diseases