Polyhydroxyalkanoate or PHA is produced through microbial fermentation of sugar and lipid where in nature it is stored as energy and carbon source for microorganisms. Most of the carbon feedstock used for PHA production are derived from biomass as they remain the cheapest carbon source to date. In this study, nipa palm sap was proposed as an alternative carbon feedstock since it is underutilized and widely distributed along river estuaries in Malaysia. This nipa sap contains high sugar content and essential nutrients which are required for PHA production. The aim of this work was to explore potential of nipa sap as a carbon source and to investigate effect of added and non-added nutrient nipa media on PHA production during batch fermentation using Cupriavidus necator DSM545. Extraction of PHA using chloroform showed that 2 g/L of PHA was recovered when nipa added with nutrient was used while nipa only media produced 2.16 g/L of PHA. All the samples showed presence of PHA carbonyl band (C=O) from extracted PHA granules by using FTIR while peak obtained using UV Spectrophotometer confirmed the presence of PHA. These findings proved that nipa palm sap as a novel and alternative carbon source for PHA production.

The world was astounded by the emergence of the deadly virus COVID-19 at the end of 2019. In March 2020, Malaysia’s first Movement Control Order (MCO) was initiated to stop the spread of the virus that ended in June 2021. Hence, this paper was initiated to study the impact of the pandemic and MCO on the generation of waste in Pasar Awam Maharani Muar (PAMM). The waste generation rate and the trend of waste accumulation according to different categories were recognised. The PAMM operates 8 hours daily, and the area strictly observes Standard Operating Procedures (SOP) established by the government. The compositional study was performed two times for 14 days in a month. The solid waste was segregated, and the weight were measured accordingly. The average total solid waste generated from 30 stalls was around 1.5 tonnes daily. It was further established that 38.5% of the waste comprised of chicken and fish waste, 36.3% formed inorganic waste, and 25.2% constituted vegetable and fruit waste. Several limitations were acknowledged in this research which was the short operational time, unpredictable weather, public holidays, and the closure of PAMM on Sundays. Observations also showed that some stall owners were highly mindful of the solid waste segregation and some of the organic wastes were reused as ruminant feed and some for composting.

Waste biomass are highly valuable and have potential to be converted to organic fertilizers or compost. This is a great alternative to replace the uses of commercial chemical fertilizers towards sustainable agriculture. However, due to its complex molecular structure and high lignin content, it hinders full decomposition of these wastes into mature compost. Therefore, subcritical water (SCW) pre-treatment was studied to enhance the hydrolytic degradation of biomass waste such as rice straw, banana peel, and chicken feathers to be converted into mature compost within a shorter time. Validation on the maturity of the treated substrates and measurements of the level of phytotoxicity in the compost were studied based on the germination index (GI) of Japanese mustard seeds. Results showed that all treated substrates provided high GI of more than 60% at its optimum concentration which indicates the significant contribution of SCW pre-treatment to produce effective mature compost.