The Effect of Mixed Biological Pretreatment and PEG 4000 on Reducing Sugar Production from Coffee Pulp Waste

Abstract

Biological methods using bacteria and fungi are regarded as more economically viable and environmentally friendly alternatives for improving lignocellulosic degradation. Coffee pulp waste (CPW) as a lignocellulosic biomass is abundant and has potential as a reducing sugar feedstock. However, it contains lignin as a matrix polymer, which associated with pectin and cover the cellulosic microfibrils and make it difficult to be digested during the bioprocess. In this study, the performance of biological pretreatment in reducing lignin and pectin using a coculture of Bacillus subtilis (BS), Aspergillus niger (AN), or Trichoderma reesei (TR) has been investigated. The pretreatment of the CPW was made using various microbial ratios in an aerobic stirred-bioreactor and incubated at 30 o C, pH 5 for 7 days. Removal of lignin and pectin was analyzed during the pretreatment process. PEG 4000 as a surfactant was used and its effect on the yield of reducing sugar production from pretreated CPW using a A. niger and T. viride (TV) co-culture with a surfactant to substrate ratio of 1:1 (w/w) was investigated. A culture without surfactant was used as a control. The results reveal that the best lignin and pectin removal was 99.9%, when using a co-culture of AN and TR with a ratio of 1:1 (v/v) and of BS and TR with a ratio of 2:1 (v/v). The cellulose content of CPW in these co-cultures was 86.99% (w/w) and 81.61% (w/w), respectively, and the reducing sugar concentration obtained was 12.5 g/L and 9.74 g/L respectively. In further hydrolysis of pretreated CPW using a AN:TV (2:1) coculture with the addition of surfactant, the yield of reducing sugar obtained was higher than that of the control, at 20.69%. Use of PEG 4000 as a surfactant had a positive effect on enhancing the yield of reducing sugar from coffee pulp waste.

Comparison of Ozone Pre-Treatment and Post-Treatment Hybrid with Moving Bed Biofilm Reactor in Removal of Remazol Black 5

“…The ozone processing as pretreatment used to obstruct organic matter into biodegradable organic. This also happened in previous research, which stated that chemical or physical processes could not provide selective removal, they were expensive, and not environmentally friendly (Iswanto et al, 2019). Ozonation as a post-treatment after the MBBR processing aims to remove recalcitrant organic residues that cannot be degraded in the ozonation as a pre-treatment and the process of MBBR.…”

Coffee Pulp: An Industrial By-product with Uses in Agriculture, Nutrition and Biotechnology

“…The use of coffee pulp as a substrate for phosphate solubilizing microorganisms (Cisneros-Rojas et al, 2016) [Kocuria sp, Bacillus subtilis (Cisneros-Rojas et al, 2017b) , (Cisneros-Rojas et al, 2017a) and S. diversispora, P. ochrochloron (Cisneros-Rojas et al, 2017a)] has also been studied; and has been reported to improve the availability of phosphorus for the development of coffee seedlings (Cisneros-Rojas et al, 2016, 2017a. Studies on the effects of Bacillus subtilis (BS), Aspergillus niger (AN), or Trichoderma reesei (TR), and PEG 4,000, have also been reported, with PEG 4000 showing better performance in reducing sugar production than the pulp waste alone (Iswanto et al, 2019a). Another surfactant, Tween 80, has shown improvements (Widjaja et al, 2019).…”

Mini-electronic Tongue Used to Discriminate between Coffee Samples of Different Geographical Origin

“…Coffee is undoubtedly one of the most popular drinks around the world, and for this reason, it has been widely studied (Mahachandra et al, 2017;Iswanto et al, 2019;Haryuni et al, 2019). Its commercialization occupies a very important place in the economies of countries like Colombia, Brazil, and Vietnam, among others.…”