There is an increasing concern about fossil energy and products derived from it. The plastic industry depends on oil, and produced plastics cannot degrade naturally. An alternative to plastics from oil is the use of bioplastics, which can be degradable. The bibliometric study of the publications related to bioplastics carried out in this paper shows that research on this topic is growing both in developed (USA, European Union, and Canada) and in developing countries (China, India, Thailand, and Malaysia), mostly following the implementation of bioeconomy standards and labels by their governments. The main authors and the collaborations they have worldwide are also presented here. The research carried out in this paper is not only devoted to technological aspects but also to economic aspects and inhabitant ratios. Trends in publications, by country and authors, are analyzed. Finally, this paper also studies the countries governmental policies and how they impact the bioplastic field.
Cow manure is an abundant residue and poses a problem regarding recycling. Intensive animal farming produces manure, which, if not properly managed, can contaminate nearby water bodies and soils with nutrient excess. There are 1.9 billion cattle worldwide, with a calculated capacity to produce 7.6 billion tons per year. Feeding of these cows is carried out mainly with cellulosic material. Therefore, cow manure contains an important fraction of lignocellulose. Cow manure can be valorized using such lignocellulosic fractions as the raw material of several fermentative processes. This fraction can be transformed into sugar, which can, in turn, be used to feed lactic acid bacteria (LAB). LAB produces lactic acid (LA), which can later be polymerized to poly(lactic acid) (PLA), a bioplastic with promising market forecasts. This review describes the most updated processes for all of the necessary steps to produce lactic acid from lignocellulosic biomass with LAB. Key process parameters to obtain PLA from lignocellulose are reviewed and analyzed herein, including lignocellulosic fraction extraction, sugar transformation, pretreatment, hydrolysis, fermentation, purification, and polymerization. This review highlights the potentiality to obtain lignocellulose from cow manure, as well as its use to obtain PLA.
The production of cow manure far exceeds the quantity that can be utilized in primary applications such as fertilizer or for the generation of biogas. As a result, alternative value-added applications are being investigated. The purpose of this study is to evaluate the production of lactic acid, using cow manure as the raw material. The methodology involved the implementation of thermochemical pretreatment for the cow manure, followed by simultaneous saccharification and fermentation for lactic acid production. Response surface methodology based on a central composite design was employed to analyze the simultaneous saccharification and fermentation process. The factorial design of the experiments was carried out with three factors, cow manure concentration, temperature, and enzyme concentration, with 80 g·L−1, 50 °C, and 212.5 IU/gCMDry Matter as central point values, respectively. Following the addition of Bacillus coagulans DSM2314 inoculum to enzymatically hydrolyzed cow manure at pH 5.0, after a 24 h period the concentration of lactic acid was recorded at 13.65 g·L−1, with a conversion efficiency of 33.1%. Studies were conducted until 48 h to analyze time impact. Characterization studies for native cow manure and that pretreated using acid reagent were conducted. Sugar content and by-product formation were analyzed, resulting in 23.24 g·L−1 of sugar remaining as the maximum after fermentation, while low values of furfural (1.04 g·L−1), 5-hydroxymethylfurfural (1.35 g·L−1), and acetic acid (1.45 g·L−1) were found. Optimal conditions were calculated at 24 and 48 h with R software, obtaining the lactic acid, with yields of 13.4 g·L−1, 36.28% (for 24 h) and 15.27 g·L−1, 32.76% (for 48 h), respectively. Experimental and statistical studies of enzymatic hydrolysis and fermentation stated that cow manure was a feasible substrate for the production of lactic acid.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.