BACKGROUND: Chemical chitin extraction generates large amounts of wastes and increases partial deacetylation of the product. Therefore, the use of biological methods for chitin extraction is an interesting alternative. The effects of process conditions on enzyme assisted extraction of chitin from shrimp shells in a systematic way were the focal points of this study.

Background: Succinic acid is a crucial platform chemical for production of various industrially significant compounds. For a sustainable and eco-friendly process, succinic acid synthesis has been shifted towards the fermentative route using renewable biomass substrates. Pineapple consumption and processing generate an immense amount of waste from its non-edible peel portion. As a carbon source, pineapple peel can be valorized for succinic acid bioproduction. Results: The hydrothermal pretreatment (121°C, 15 min) of pineapple peel waste resulted in the highest sugar release of 35.22 g/L (18 g/L glucose and 17 g/L fructose). The subsequent fermentation of pineapple peel hydrolysate was performed by a natural succinic acid producer, Actinobacillus succinogenes TISTR 1994. When the non-detoxified hydrolysate was used as a sole carbon source, 6.21 g/L of succinic acid was produced from 26.16 g/L of sugars. Additional supplementation of 9 g/L mixed nitrogen source enhanced the formation of succinic acid to 9.96 g/L from roughly the same amount of sugar. The current production conditions using mainly hydrolysate-based medium gave the succinic acid yield of 0.39 g/g sugar suggesting feasibilities for further improvement. Conclusion: Bio-based succinic acid production was attempted for the first time using the solid pineapple waste as a main starting material. Results demonstrated a proof of concept that the abundant pineapple peel waste can serve as a renewable substrate for a low-cost, value-added bioconversion to succinic acid. Optimization of nutritional composition in hydrolysate is necessary to enhance the yield of succinic acid in future studies.

The pineapple industry generates large amounts of unusable waste (peel and core) with adverse environmental impacts. This experimental study aims to systemize the potential of ultrasonic-assisted alkaline pretreatment for xylose production from pineapple peel waste. The best condition for single alkaline pretreatment (1 % NaOH w/v, 100 °C, 60 min) has obtained hemicellulose, cellulose, and lignin composition at 34.80 %, 32.16 %, and 8.66 %, respectively, retained in the biomass. Meanwhile, a combination of alkaline (1 % NaOH, w/v) and ultrasonic (frequency 40 kHz, 45 min) pretreatment has obtained the percentage yield of hemicellulose and lignin at 51.15 % and 7.15 %, respectively. Both single alkaline and ultrasonic-assisted alkaline pretreated samples were subsequently hydrolyzed with 2 % H2SO4 (w/v). After acid hydrolysis for 30 min, the maximum xylose concentration of 48.85 g.L-1 was achieved by using ultrasonic-assisted alkaline pretreatment, while single alkaline pretreatment contributed to the lowest yield of xylose (37.11 g.L-1). It is shown that the ultrasonic-assisted alkaline treatment is more favorable than single alkaline pretreatment as it can produce high xylose concentration after the subsequent hydrolysis. These results indicated that ultrasonic-assisted alkaline pretreatment and its subsequent acid hydrolysis were appropriate for producing xylose from pineapple peel waste.