Successful commercialization of microalgal bio-industry requires the design of an integrated microalgal biorefinery system that facilitates the co-production of biofuels, high-value products and industrial chemicals from the biomass. In this study, we investigated the use of sugar hydrolysate obtained from enzy-How to cite this paper: Kassim, M.A., Rashid, M.A. and Halim, R. (2017) Towards Biorefinery Production of Microalgal Biofuels and Bioproducts: Production of Acetic Acid from the Fermentation of Chlorella sp. and Tetraselmis suecica Hydrolysates. Green and Sustainable Chemistry, 7, 152-171. Open Access M. A. Kassim et al. 153 tegrated microalgal biorefinery system.

Magnifera indica cv. Harumanis is one of the most commercially grown mango cultivar in Malaysia due to market demand and price. However, the fruit supply never meets the demand as Harumanis is highly sensitive towards the climate and only grows in Perlis and part of Kedah. Crop productivity and development are mainly related to climatic variables where temperature and precipitation are the most importance. Temperature and precipitation distribution pattern affect flowering, fruit set, fruit growth and also fruit development. This study evaluates the relationship between temperature and precipittaion distribution pattern towards development of Harumanis growth stages including flowering and fruit development aspects in Zone 1 (area with a clear dry season up to three or four months) and Zone 2 (area with a clear dry season between one to two months). Thermal calendar based on daily and accumulated growing degree days (GDD) used to predict growth stages. Results indicate that Harumanis need a hot and dry environment (high temperature with less precipitation) during reproductive stage. However, there is no significant difference between Zone 1 and Zone 2 on the GDD required during every growth stages. On yield and fruit quality aspects, Zone 1 produced higher yield and better quality than Zone 2 due to the environmental factor even though there is no significant difference. Future study needs to be done as this information together with projection of future climate change scenarios are crucial in developing Decision Support Tool (DST) to guide the farmers in planning their crop management practices for the upcoming season.

Aims: This experiment aimed to study the effect of girdling, paclobutrazol application, combined methods, and untreated trees on physiological response, vegetative and reproductive growth, and fruiting. Place and Duration of Study: This study was carried out from August 2021 to June 2022 at MARDI, Serdang, Selangor, using five years of open-field Mangifera indica cv. Harumanis trees. Study Design:  The study was arranged in the frame of  randomized complete block design with three replications and three samples per treatment; ANOVA and DMRT at p=0.05 were used for significance and post hoc comparison, respectively. Methodology: Each replication consists of: T1- No induction (Control); T2- girdling at primary branches; T3- soil drenching at 4 ml/l PBZ and T4- girdling at primary branches + soil drenching at 4 ml/l PBZ. The girdling process was performed by removing a 10 mm width ring of bark at all primary branches. Paclobutrazol (25% active ingredient) of the commercial product was used. The treatments were performed concurrently on 1st December 2021 at the same morphological size as the tree subjected to similar light exposure. Results: The combination method of girdling and paclobutrazol application had the most significant adverse effect on internode length. Nevertheless, no significant difference was observed in plant stem diameter, height, number of primary and secondary branches, and number of shoots generated from all treatments. The combined method reflected a significant reduction in stomatal conductance, rate of photosynthesis, and transpiration rate. However, the intercellular CO2 concentration of this combined method and untreated tree is significantly higher. Flowering appears on the leaf buds 90 days after the treatment for paclobutrazol application and the combined method. These methods also resulted in yield per fruit and yield per tree. Conclusion: Based on the results, the combination method of girdling and paclobutrazol application was effective to reduce vegetative growth, suppress physiological capacity, yet the most effective to produce flowering and fruit yield.

Stevia (Stevia rebaudiana Bertoni) has received great attention with the rise in demand for low-sugar food and beverage additives, and natural alternative to cane sugar and artificial sweeteners. The leaves produce intensively sweet steviol glycosides (mainly stevioside and rebaudioside A). Stevia has been reported as a short-day plant with a critical daylength of 13 h. Daylength less than 13 h causes stevia to flower early, resulting in a low leaf biomass yield and percentage of sweetener content. The effects of night interruption treatment using six light sources for 60 min daily with the aim to lengthen vegetative phase, increase plant biomass and steviol glycoside content of stevia were investigated. Night interruption was shown to extend vegetative phase from 20 days (control) to 120 days; thus, allowing accumulation of plant biomass and steviol glycosides content. Leaf biomass and steviol glycosides of all light sources treated plants increased significantly as compared to control plants especially in week 6 and 8 after treatment initiated. Fluorescent and light-emitting diode (LED) were energy-efficient and effective as light source for night interruption. Fluorescent warm white showed the highest increase in total steviol glycosides content per plant by 190-270% most probably because it contained the highest red light at 614 nm as compared to other light sources. Stevioside content was not significantly affected by drying methods but rebaudioside A content was significantly reduced by 3.38% under oven drying at 70oC. The reduction indicated that thermal degradation of rebaudioside A has occurred at higher temperature.

The impact of climate change on agricultural production will be most pronounced in tropical and subtropical regions, with numerous climate modeling studies predicting more occurrences of heat waves in the future. Elevated temperatures resulting from global warming pose a significant threat to the agricultural sector, as warmer conditions can hinder plant growth and development, leading to reduced crop yields or even crop failure under extreme circumstances. Therefore, this study aimed to determine the effects of ambient, non-heated (30 °C) and heat stress conditions (38 °C) on the plant physiological responses, growth and yield of grain corn during both the vegetative and reproductive stages. The results demonstrated that exposure to heat stress for 7 days significantly impacted the physiological performance of the plants, resulting in a substantial 46.9% reduction in net photosynthetic rate. However, prolonged exposure to heat for 28 days caused even more severe effects, with a 72.5% reduction in net photosynthetic rate. Although the effects of heat stress on vegetative growth were not apparent after 7 days, the plants exhibited severe damage after 28 days of heat stress treatment. During the flowering stage, heat stress led to significant reduction in kernel set, total kernel number, and grain weight of grain corn by 45%, 41%, and 46%, respectively. Poor and scattered kernel set on cobs during the heat stress treatment at the anthesis period indicated damage to pollen grains, failed pollination, and fertilization. These findings highlight the vulnerability of grain corn varieties cultivated in Malaysia to the negative impacts of heat stress, leading to potential losses in production yield.