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Background Dengue is a significant public health issue that is caused by Aedes spp. mosquitoes. The current vector control methods are unable to effectively reduce Aedes populations and thus fail to decrease dengue transmission. Hence, there is an urgent need for new tools and strategies to reduce dengue transmission in a wide range of settings. In this study, the Mosquito Home System (MHS) and Mosquito Home Aqua (MHAQ) formulations were assessed as commercial autodissemination traps in laboratory and small-scale field trials. Method Multiple series of laboratory and small-scale field trials were performed to assess the efficacy of MHS and MHAQ exposed to Ae. aegypti. In the laboratory trials, various parameters such as fecundity, fertility, wing size, oviposition preferences, residual effects, and MHAQ transference to other containers through controlled experiments were tested. For small-scale field trials, the efficacy of the MHS and MHAQ approaches was determined to ascertain whether wild mosquitoes could transfer the MHAQ formulation from MHS stations to ovitraps. Results The data revealed that Ae. aegypti was highly susceptible to low concentrations of MHAQ formulations and had a residual effect of up to 3 months, with MHAQ exposure affecting fecundity, fertility, and mosquito wing size. In the oviposition studies, gravid females strongly preferred the hay infusion compared to tap water and MHAQ during egg-laying in the laboratory. Nevertheless, the use of commercial MHAQ by MHS was highly attractive in field settings compared to conventional ovitraps among local Aedes spp. mosquitoes. In addition, MHAQ horizontal transfer activities in the laboratory and small-scale field trials were demonstrated through larval bioassays. These findings demonstrated the potential of MHAQ to be transferred to new containers in each study site. Conclusion This study provided proof of principle for the autodissemination of MHAQ. Through further refinement, this technique and device could become an effective oviposition trap and offer an alternative preventive tool for vector control management. Graphical abstract

Jatropha curcas is a medicinal plant with many therapeutic properties such as anti-inflammatory, anti-malaria, anti-cancer and antioxidant. The root extract has been shown to possess high anti-inflammatory activity. Previously, the compounds responsible for this activity have not been fully elucidated. Two fractions (Fraction 1 and Fraction 2) obtained from a preparative HPLC of the root extract showed significant anti-inflammatory and cytotoxic activities in RAW 264.7 murine macrophage cells with Fraction 1 giving higher nitric oxide (NO) inhibition compared to Fraction 2 and L-NAME. Further purification steps involving column chromatography, thin layer chromatography and analytical HPLC of Fraction 1 produced two fractions labeled as Fraction A and Fraction B. Both fractions showed anti-inflammatory activity without cytotoxic activity in RAW 264.7 cells. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis showed that Fraction A contained a group of 18 carbon fatty acid compounds consisting of 2 oxooctadecanoic acids; 15, 16 dihydroxy 9Z, 12Z octadecadienoic acid; octadecadienoic isomer and 15,16 dihydroxy 9Z, 12Z octadecadienoic acid, 15S, 16S. The 18-carbon fatty acid structure was confirmed by nuclear magnetic resonance (NMR) spectral data. The IC50 value of compounds in Fraction A for anti-inflammatory activity in RAW 264.7 cell line was 434.8±0.75 µg/mL. From the analysis, it can be concluded that Fraction A can be classified under 18 carbon long chain fatty acid group based on LC MS/MS and NMR analysis. This active compound shows an inhibition towards NO activity.

The application of microorganisms in azo dye remediation has gained significant attention, leading to various published studies reporting different methods for obtaining the best dye decolouriser. This paper investigates and compares the role of methods and media used in obtaining a bacterial consortium capable of decolourising azo dye as the sole carbon source, which is extremely rare to find. It was demonstrated that a prolonged acclimation under low substrate availability successfully isolated a novel consortium capable of utilising Reactive Red 120 dye as a sole carbon source in aerobic conditions. This consortium, known as JR3, consists of Pseudomonas aeruginosa strain MM01, Enterobacter sp. strain MM05 and Serratia marcescens strain MM06. Decolourised metabolites of consortium JR3 showed an improvement in mung bean’s seed germination and shoot and root length. One-factor-at-time optimisation characterisation showed maximal of 82.9% decolourisation at 0.7 g/L ammonium sulphate, pH 8, 35 °C, and RR120 concentrations of 200 ppm. Decolourisation modelling utilising response surface methodology (RSM) successfully improved decolourisation even more. RSM resulted in maximal decolourisation of 92.79% using 0.645 g/L ammonium sulphate, pH 8.29, 34.5 °C and 200 ppm RR120.

Ammonium and manganese may cause the aesthetic deterioration of drinking water quality if their penetration into the water intake is not controlled. The current physical chemical methods may be unable to treat polluted raw water alone, so a biological method is used to bolster the current physical capabilities. In this study, the biological removal of ammonium and manganese was performed using a slow sand biofilter (SSB) and optimized based on a central composite design (CCD) with response surface methodology (RSM). RSM was used to study the interaction among the process variables, namely, the feed concentration of ammonium (NH4-N) and manganese (Mn), the aeration rate (AR) and retention time (RT). The optimum conditions suggested by the response model were 2.01 mg NH4-N/L and 3 mg Mn/L feed concentrations, a 6 L/min AR and a 9.45 h RT. The condition resulted in an 89% and 98% reduction of ammonium and manganese, respectively. The microbial community attached on the SSB was identified using a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. Eight strains were obtained and identified as closest to Clostridium sp., Desnuesiella sp., Aeromonas sp., Pseudoalteromonas sp., Romboutsia sp., and Plasticicumulans sp. Of the bacteria identified in the community, Aeromonas sp. is known to have the ability to oxidize ammonium, and Pseudoalteromonas sp. is involved in oxidation of soluble Mn2+ to insoluble Mn4+.

Azadirachta indica, or Neem, is a natural plant commonly used in medicine and pesticides due to the useful compounds it contains. This study aimed to determine the performance of Neem leaves as a natural coagulant in the removal of turbidity, total suspended solids (TSS) and colour from real aquaculture effluent. The experiment was conducted to determine the effect of mass ratio of the TSS (mg)/mass of coagulant (mg) on the removal of turbidity, TSS and colour, in which the ratio is calculated based on the TSS concentration as an index of aquaculture pollution. The experiment was carried out with a ratio range of 0.1 to 1000 mg TSS per mg coagulant and a total volume of 500 mL. The operational conditions were fixed at 180 rpm and 3 min for rapid mixing, 10 rpm and 20 min for slow mixing and settling time from 30 min to 60 min. The results showed a turbidity removal of 82.7%, TSS removal of 81.37% and colour removal of 65.8% at an optimum ratio of 1000 and coagulant dosage of 0.3 mg/L. For comparison, the performance of alum was also tested and showed higher turbidity, TSS and colour removals of 99.7%, 98.8% and 97.3%, respectively, based on the optimum ratio of 1 with a dosage of 362.7 mg/L. Both coagulants showed a similar optimum settling time of 30 min. From these results, it is clearly seen that Neem has a high potential for use as a coagulant, indicating further exploration to optimize the extraction of active compounds from the leaves.

Turbidity is a common pollutant parameter in water and wastewater treatment that can be reduced through flocculation. This research was conducted to characterise and analyse the potential of bioflocculant-producing bacteria isolated from aquaculture effluent. Samples were taken from two different aquaculture farms that represent brackish and freshwater cultures. A total of 21 different colonies were obtained from all samples. Screening of flocculation activity showed the potential of WS5 to be a bioflocculant agent to remove turbidity from artificial turbid water. One variable at a time analysis was performed to assess the capability of WS5 in different initial turbidity and bioflocculant doses. In comparison with low turbid water with 5% v/v bioflocculant dose (in 5000 NTU turbidity), WS5 exhibited better performance in high turbid water, thereby resulting in the most optimum flocculation activity of 72.5%. The increment in bioflocculant dose of up to 10% did not contribute to the flocculation activity significantly. The increment in particle size distribution for the suspension from before to after treatment with bioflocculant provided evidence that the process of flocculation had occurred effectively. Genomic analysis of selected potential bacteria using BLAST and phylogenetic tree has identified WS5 as Serratia marcescens and has been confirmed as a rod-shaped bacterium. FT-IR spectra and zeta potential analysis indicated that the produced bioflocculant is categorised as anionic bioflocculant with polymer bridging suggested as the main mechanism during turbidity removal.

In this study, two native duckweeds (Lemna minor and Azolla pinnata) were cultivated in Palm Oil Mill Effluent (POME) to extract nutrients from the effluent. Five grams of A. pinnata and 2 g of L. minor were transferred to 2 L POME (Initial concentrations: 198 mg/L COD, 4.3 mg/L nitrates, pH 9.53, 4 mg/L phosphate, 2.98 mg/L ammonia) with four different dilutions (2.5%, 5%, 10%, 15%) under greenhouse conditions. Samples of POME were taken every two days up to 10 days. Growth parameter, phosphate, ammonia, nitrates, pH, and COD were monitored within 10 days to select the most suitable growth medium for both plants. Results showed that 2.5% POME dilution had positive effect on L. minor growth and A. pinnata (wet weight increased by 8.7 g and 9.8 g, respectively), with all plants able to survive until the final day of exposure. The highest removal of ammonia was accomplished in 5% POME dilution by A. pinnata (98%) and L. minor (95.5%). The maximum phosphate removal was obtained in 10% POME dilution with 93.3% removal by A. pinnata and 86.7% by L. minor. Significant COD removal in 15% POME was obtained by L. minor (78%) and A. pinnata (66%). Both plants responded positively to the phytoremediation process, especially for A. pinnata which showed significant decreases in all parameters. The nutrient extraction by both plants from POME showed a positive effect on growth parameter, which has further promising potential to be used as animal feedstock.

Biochar has the potential to increase crop yields on degraded, tropical soils. It can be readily produced in rural community settings using low-cost technology and is most economically feasible if produced from local biomass or waste residues. Biochar was produced from Leucaena biomass using low-cost pyrolysis and sequential pot experiments were then conducted in Malaysia on three degraded soils. We first evaluated the effect of Leucaena biochar on yields of Amaranthus, a leafy vegetable crop and measured changes to soil pH and nutrient availability over two growth cycles. We then tested whether any yield response to biochar was dependent upon the rate of biochar or fertilizer application. We found that biochar application at 30 t ha−1 with maximal fertilizer increased yields between 17 and 53% on very strongly acidic soil. Biochar added at 15 t ha−1 with maximal fertilizer increased yield by 54% on strongly acidic soil whilst there was no significant yield response on fertilized, slightly acidic soil. Unfertilized biochar treatments showed small yield responses across all soils over 2 growth cycles (9–11%), but yields were much lower than in fertilized treatments. Biochar also decreased short-term N availability when applied with fertilizers, which may improve nitrogen retention and substantially increased soil pH. This may reduce mobility of Fe, Mn and Al ions, which were negatively associated with yield. Our results suggest that Leucaena biochar can elicit a positive crop yield response but only when combined with fertilizer additions on very strongly to strongly acidic tropical soils.

This study was conducted to determine the phytoremediation performance of a continuous two-stage constructed wetland system using two tropical plants native to Malaysia (Phragmites karka and Eichhornia crassipes) to remove contaminants from real coffee industry effluent. The coffee effluent used in this study had a pH value of 4.4 with total suspended solids of 399.3 mg/L, colour of 1730 ADMI, and COD and BOD values of 13,000 and 1720 mg/L, respectively. The system was fed continuously with coffee industry effluent at a volumetric flowrate of 4.1 L/day to maintain the hydraulic retention time at 3 days for Phragmites karka and 4 days for Eichhornia crassipes. The two-stage plant system was capable of removing 94%, 79% and 95% of suspended solids, colour and COD, respectively. Phytotechnology undoubtedly has the potential to be used in the treatment of coffee industry effluent.

Microorganisms that have the potential to improve plant productivity and health are known as plant growth-promoting rhizobacteria. Rhizobacteria play a major role in phytoremediation process by increasing the phytoremediation efficiency, thus the need to identify the superior rhizosphere bacteria has been gaining serious attention. In the current study, Scirpus grossus were exposed to a series of lead-contaminated sand (50, 100, 150, 200 and 300 mg/L) in plastic crates in greenhouse enviroment. Four weeks after exposure, the plants could sustain with toxicity of lead contamination by as much as 300 mg/L. Twenty two colonies of rhizobacteria were isolated from plant roots of Scirpus grossus. The rhizobacteria were characterised based on cell and colony observation. Identification of rhizobacteria was carried out based on analysis of 16S rDNA sequences and were identified as Aeromonas taiwanensis isolate 5E, Bacillus sp. Isolate 7G, Bacillus cereus isolate 8H and 3C , Bacillus velezensis isolate 9I, Bacillus proteolyticus isolate 4D, Bacillus stratosphericus isolate 14N, Bacillus megaterium isolate 11K , Pseudomonas sp. Isolate 12L , Enterobacter cloacae isolate 13M and isolate 16P, Bacillus aerius isolate 15O and Lysinibacillus sp. isolate 10J. The highly lead-resistant rhizobacteria were identified as Bacillus proteolyticus isolate 4D, Bacillus velezensis isolate 9I and Lysinibacillus sp. isolate 10J , which can tolerate against high concentration of lead (300 mg/L). The results showed that these highly lead-resistant rhizobacteria have potential to produce plant growth-promoting traits and have a ability to help S. grossus growth and productivity.

Heterobostrychus aequalis is a major pest of seasoned hardwood. It attacks many timber and wood from other plant species and caused damage to a broad range of wood products. Their attacks are confined to starch-rich sapwood and often unsuspected until the emergence hole and frass is produced. The repeated introduction of this pest into new areas indicates that it is poorly inspected and ignored. In some cases, this species succeed in establishing its population in the wild. Hence, by providing the world wide distribution of this pest could be the pioneer step in developing better prevention, monitoring, quarantine and control programmes. From the review, it was found that H. aequalis distribute dominantly in tropical and sub-tropical areas. It is widely distributed in Asia, particularly Southeast Asia to Oceania, some parts of Africa, Central America and Caribbean region. The distribution map derived indicates the limits of distribution for H. aequalis to be 40° north and south of the equator. The recent reports and records showed that this pest is potentially becoming a high-risk pest and can establish its population whenever the condition is favourable.

Background The Jatropha curcas plant or locally known as “Pokok Jarak” has been widely used in traditional medical applications. This plant is used to treat various conditions such as arthritis, gout, jaundice, wound and inflammation. However, the nature of compounds involved has not been well documented. Hence, this study was conducted to investigate the anti-inflammatory activity of different parts of J. curcas plant and to identify the active compounds involved. Methods In this study, methanol (80%) extraction of four different parts (leaves, fruits, stem and root) of J. curcas plant was carried out. Phenolic content of each part was determined by using Folin-Ciocalteau reagent. Gallic acid was used as the phenol standard. Each plant part was screened for anti-inflammatory activity using cultured macrophage RAW 264.7 cells. The active plant part was then partitioned with hexane, chloroform, ethyl acetate and water. Each partition was again screened for anti-inflammatory activity. The active partition was then fractionated using an open column chromatography system. Single spots isolated from column chromatography were assayed for anti-inflammatory and cytotoxicity activities. Spots that showed activity were subjected to gas chromatography mass spectrophotometry (GC-MS) analysis for identification of active metabolites. Results The hexane partition from root extract showed the highest anti-inflammatory activity. However, it also showed high cytotoxicity towards RAW 264.7 cells at 1 mg/mL. Fractionation process using column chromatography showed five spots. Two spots labeled as H-4 and H-5 possessed anti-inflammatory activity, without cytotoxicity activity. Analysis of both spots by GC-MS showed the presence of hexadecanoic acid methyl ester, octadecanoic acid methyl ester and octadecanoic acid. Conclusion This finding suggests that hexadecanoic acid methyl ester, octadecanoic acid methyl ester and octadecanoic acid could be responsible for the anti-inflammatory activity of the J. curcas root extract.