Bioconversion of Single Cell Protein from Underutilised Seaweed Turbinaria sp. using Natural Palmyrah Toddy Yeast

Abstract

This study was aimed to produce Single Cell Protein (SCP) from underutilied, abundantly found marine seaweed Turbinaria sp. using natural yeast from palmyrah (Borassus flabellifer) toddy. Turbinaria sp. were collected, sun-dried, ground to powder form and Turbinaria solution was made by mixing distilled water and this was used as a growth medium throughout the experiment without adding any supplements. The experiments were performed in a shaking incubator with the fermentation medium of Turbinaria sp. 100 g/L (10%) inoculated with 10 mL natural palmyrah toddy. Fermentation was carried out at 29o C for 72 h and the crude protein content was determined using Kjeldahl apparatus (38.46%). When the growth temperature was optimised at 35o C, crude protein yield obtaine was significantly increased by 1.36 times than the initial non-optimised condition with temperature 27oC. When fermentation time was optimised as 48 h (44.33%), crude protein yield was significantly increased by 1.14 times than the initial fermentation time (24 h-38.55%). When different combinations of Turbinaria sp. media and inoculum ratio (55:05, 50:10, 40:20, 30:30 and 20:40) were used as medium, crude protein yield was significantly increased by 1.44 times (50:10-43.72%) than the initial media inoculum ratio (55:05-30.21%). When initial pH of the media was changed (5.0, 6.0, 7.0, 8.0 and 9.0), significantly higher relative crude protein yield was obtained with the initial pH value 6.0 (Turbinaria medium-90.97%). Amino acid analysis revealed that the SCP produced from the Turbinaria medium had all the essential amino acids with comparatively higher amount of methionine (3.9%) and lower amount of threonine (0.2%). Vitamin B analysis revealed that SCP yield from Turbinaria medium contained thiamin (0.85 mg/100 g) and riboflavin (3.2 mg/100 g). After the optimisation of culture growing conditions and media composition, SCP production from the excessively grown, underutilised seaweed Turbinaria, was significantly increased by 1.13 times (from 38.46 to 43.72%) with palmyrah toddy mix.

Key words: crude protein, palmyrah toddy mix, single cell protein (SCP), Turbinaria sp.