Investigating the effect of several Palm Oil Mill Effluent (POME) dilutions on biomass and specific growth rate of C. sorokiniana

High amount of turbidity was identified as one of the important factor affecting the successful cultivation of microalgae in palm oil mill effluent (POME). In this study, Chlorella sorokiniana was cultivated in POME, under different dilutions of 80, 60, 40 and 20% (v/v) with distilled water. The aim of the study is to investigate the effect of POME turbidity and the dilutions on the specific growth rate of microalgae. The results found that, C. sorokiniana grew on both sterilized and unsterilized condition. The result of the batch experiment showed that, POME turbidity of 45 NTU produce the maximum specific growth rate by C. sorokiniana of 0.14 d-1, which correspond to biomass production of 4.06 g/L and 0.2 d-1, which correspond to biomass production of 5.94 g/L in sterilized and unsterilized POME respectively. The POME of high turbidity concentration of 98 NTU yield only 0.07 d-1 maximum specific growth rate of algae. Results of this study identified 80% dilution as the optimal medium that can enhance maximum biomass production in POME. This could be useful in reducing the cost of bioenergy generation

Humanitarian disaster: mental health disorders at primary healthcare clinic

INTRODUCTION: Little is known about the mental health of Rohingya refugees attending the Malaysian Field Hospital primary health clinic after arriving in Bangladesh. The objectives of this study were to assess the prevalence of mental health disorders, somatic symptoms and to ascertain the determinants of mental health disorders among the Rohingya refugee community attending the primary health clinic. MATERIAL AND METHODS: A cross-sectional, face-to-face interview using the DASS-21 Questionnaire was conducted among 180 random samples of patients from the Rohingya community. Symptoms of illnesses were recorded before giving the appropriate treatment. Data was collected to obtain the prevalence of mental health disorders, including anxiety, depression, somatic symptoms, and to study the association and predictors of mental health disorders. RESULTS: 70.6% of respondents reported having mental health disorders. 70% presented with anxiety and 51.6% had depression. Among the respondents with mental health disorders, 70.8% presented with somatic symptoms. Mental health disorders were associated with female gender, older age, formal education, unemployment, high number of households, being in Bangladesh one year or less, and presence of somatic symptoms. Being in Bangladesh one year or less (AOR, 11.73; 95% CI 3.38–40.71) and presence of somatic symptoms (AOR, 12.1; 95% CI: 4.02 to 36.44) were significant predictors of mental health disorders. CONCLUSIONS: The prevalence of mental health disorders among Rohingya refugees attending the primary health care clinic was high, and they presented with somatic symptoms

Initial study on the growth of haematococus pluvialis for astaxanthin production

This research emphasizes the identification of best nutrients among the four medium that will be used for a better growth rate of Haematococcus pluvialis. The growth rate of H. pluvialis is controlled or regulated by the physical and chemical parameters. Each of the parameters gives different yield productions to H. pluvialis. Different types of medium composed of different nutrients composition resulted in various maturation and growth rate of H. pluvialis monitored by the change in the optical density at 750 nm over time. The best medium was Rudic`s medium which gave OD750nm at 0.757 after 20-day culture. Then, Bold Basal medium, Basal medium and BG11 medium were followed as 0.677 at day 20, 0.358 at day 12 and 0.162 at day 15, respectively. Besides, this research also focuses on identifying the most suitable carbon source. Sodium acetate was found to be the best in the cultivation of H. pluvialis with the maximum absorbance of 0.99 in Rudic`s medium. The higher cell density cultures was achieved with 4 g/L concentration of sodium acetate. Carbon source also promoted better maturation process of H. pluvialis which will enhance yield of astaxanthin production in a shorter period of time. The primary composition that contribute to the high growth of H. pluvialis can be determined by adding 50% of concentration CaCl2 in the medium with control flask contain 0.0585 g/L concentration of CaCl2. The growth of H. pluvialis at day 9 was shown to increase by 27%. with absorbance of 0.301 if compared to control which gave absorbance 0.236. High concentration of CaCl2 contribute to high growth of H. pluvialis

Statistical optimization of enzymatic degradation process for oil palm empty fruit bunch (OPEFB) in rotary drum bioreactor using crude cellulase produced from Aspergillus niger EFB1

Oil palm empty fruit bunch (OPEFB) was pretreated with 2% (v/v) HNO3 and degraded by Aspergillus niger EFB1 crude cellulase. Through 2 Level Factorial Design (2LFD), it was found that OPEFB concentration, temperature, incubation time, concentration of Tween 80 and agitation speed have significant effect in reducing sugar production. A standard Response Surface Methodology (RSM) design known as Central Composite Design (CCD) was used to optimize the enzymatic degradation condition of OPEFB in rotary drum bioreactor. Reducing sugar level of 1.183 g/L was obtained with the following optimized degradation conditions: 1.95% (w/v) OPEFB, 0.5% (v/v) Tween 80, 55 °C, 87.5 rpm in the incubation period of 3 days and 16 h. The optimal degradation condition improved reducing sugar production by 1.07 fold compared to that before optimization in shake flasks culture. The optimization strategy of enzymatic degradation of OPEFB inside rotary drum bioreactor led to increase in glucose, xylose, arabinose, galactose and mannose production by 3, 2.5, 1.64, 19.37 and 22.52 fold, respectively. The improvement in reducing sugar and polyoses production were comparable with the reduction in OPEFB cellulose and hemicellulose content by 89.32% and 48.17% respectively after enzymatic degradation in optimized condition

Production of cellulases and xylanase by Aspergillus fumigatus SK1 using untreated oil palm trunk through solid state fermentation

Direct utilization of untreated oil palm trunk (OPT) for cellulases and xylanase production by Aspergillus fumigatus SK1 was conducted under solid-state fermentation (SSF). The highest activities of extracellular cellulases and xylanases were produced at 80% moisture level, initial pH 5.0, 1 × 108 spore/g (inoculum) with 125 μm of OPT as sole carbon source. The cellulases and xylanase activities obtained were 54.27, 3.36, 4.54 and 418.70 U/g substrates for endoglucanase (CMCase), exoglucanase (FPase), β-glucosidase and xylanase respectively. The crude cellulases and xylanase required acidic condition to retain their optimum activities (pH 4.0). Crude cellulases and xylanase were more stable at 40°C compared to their optimum activities conditions (60°C for FPase and 70°C for CMCase, β-glucosidase and xylanase). SDS-PAGE and zymogram analysis showed that Aspergillus fumigatus SK1 could secrete cellulases (endoglucanase, exoglucanase and β-glucosidase), xylanase and protease. Enzymatic degradation of alkaline treated OPT with concentrated crude cellulases and xylanases resulted in producing polyoses

Enhanced astaxanthin production by oxidative stress using methyl viologen as a reactive oxygen species (ROS) reagent in green microalgae Coelastrum sp.

Microalgae are known to be a potential resource of high-value metabolites that can be used in the growing field of biotechnology. These metabolites constitute valuable compounds with a wide range of applications that strongly enhance a bio-based economy. Among these metabolites, astaxanthin is considered the most important secondary metabolite, having superior antioxidant properties. For commercial feasibility, microalgae with enhanced astaxanthin production need to be developed. In this study, the tropical green microalgae strain, Coelastrum sp., isolated from the environment in Malaysia, was incubated with methyl viologen, a reactive oxygen species (ROS) reagent that generates superoxide anion radicals (O2-) as an enhancer to improve the accumulation of astaxanthin. The effect of different concentrations of methyl viologen on astaxanthin accumulation was investigated. The results suggested that the supplementation of methyl viologen at low concentration (0.001 mM) was successfully used as a ROS reagent in facilitating and thereby increasing the production of astaxanthin in Coelastrum sp. at a rate 1.3 times higher than in the control

Green Synthesis of Gold Nanoparticles Using Aqueous Extract of Garcinia mangostana

The synthesis of gold nanoparticles (Au-NPs) is performed by the reduction of aqueous gold metal ions in contact with the aqueous peel extract of plant, Garcinia mangostana (G. mangostana). An absorption peak of the gold nanoparticles is observed at the range of 540–550 nm using UV-visible spectroscopy. All the diffraction peaks at 2θ = 38.48°, 44.85°, 66.05°, and 78.00° that index to (111), (200), (220), and (311) planes confirm the successful synthesis of Au-NPs. Mostly spherical shape particles with size range of 32.96 ± 5.25 nm are measured using transmission electron microscopy (TEM). From the FTIR results, the peaks obtained are closely related to phenols, flavonoids, benzophenones, and anthocyanins which suggest that they may act as the reducing agent. This method is environmentally safe without the usage of synthetic materials which is highly potential in biomedical applications

Degradation of persistent endosulfan by isolated actinomycetes and Rhodococcuss jostii, RHA1

The property of organochlorine endosulfan which is persistent and toxic can cause environmental pollution and pose human health and has raised concern worldwide. Hence, biodegradation serves as promising tool in overcoming the problem of pesticides pollution. The effective approach of removal of endosulfan from the environment is by using Gram-positive microorganisms such as actinomycetes, predominant microorganisms found in soil habitat are less exploited and studied in biodegradation of endosulfan. The diverse metabolic diversity and unique enzymatic capabilities of actinomycetes has gained interest in biodegradation to remove the endosulfan from the environment. This study aims to isolate indigenous actinomycetes from soil habitat and screening the ability of isolated actinomycetes to degrade the endosulfan. Cameron Highland where intensive agricultural activities were carried out was chosen as the sampling site for isolation of actinomycetes that could have potential in degradation of endosulfan. Screening of the ability of endosulfan degradation by isolated actinomycetes in sulphur free broth culture and followed by determination by residual endosulfan by using GC-ECD analysis which is sensitive and specific assay in detecting the endosulfan

Immobilization of bovine serum albumin on the chitosan/PVA film

Chitosan/polyvinyl alcohol (Chitosan/PVA) blended film was prepared by direct blend process and solution casting methods. In order to reduce the swelling ratio and enhance the chemical and mechanical stability, Chitosan/PVA film was cross-linked with glutaraldehyde in order to produce Chitosan-g-PVA. Bovine serum albumin (BSA) was used as a model protein to incorporate into the Chitosan-g-PVA. The chemical structure and morphological characteristics of films were studied by FT-IR and scanning electron microscopy (SEM). Mechanical and physical properties of blended films such as tensile properties in the dry and wet states, water uptake and water contact angle measurement were characterized. Blending PVA and chitosan improved strength and flexibility of the films. Crosslinking with glutaraldehyde further improves the tensile strength and decrease the hydrophilicity of films. BSA immobilized on the Chitosan-g-PVA film was calculated as BSA encapsulation efficiency

Induction condition of secondary metabolites production in soil actinomycetes, rhodococcus jostii RHA1

Rhodococcus jostii RHA1 is a potent polychlorinated biphenyl-degrading soil actinomycete that catabolizes a wide range of compounds and represents a genus of considerable chemical and industrial interest. Genome of RHA1 contains nonribosomal peptide synthase (NRPS) genes, and polyketide synthase (PKS) genes, providing evidence that RHA1 harbor an extensive secondary metabolism as same as other actinomycetes. To elucidate R. jostii RHA1 may produce any kinds of secondary metabolites, induction condition of these secondary metabolite production genes were investigated. Type I, type III, PKS-NRPS hybrid located on chromosome, and NRPSs located on plasmid were typically induced on solid medium with specific nutrient or environment condition. On the other hands, type II PKSs located on chromosome were mainly induced on liquid medium with specific condition. These results indicated that secondary metabolites induced on specific condition on solid or liquid medium by RHA1 might play a key role of surviving under severe environmental condition