Pub Date : 2023-12-23DOI: 10.1007/s12155-023-10715-2
Jerome Dumortier, Héctor A. Ruiz, W. Vermerris
{"title":"Celebrating 15 Years of BioEnergy Research: a Journey Towards Sustainable Solutions","authors":"Jerome Dumortier, Héctor A. Ruiz, W. Vermerris","doi":"10.1007/s12155-023-10715-2","DOIUrl":"https://doi.org/10.1007/s12155-023-10715-2","url":null,"abstract":"","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139161805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-22DOI: 10.1007/s12155-023-10713-4
Isabela de L. Valente, João H. C. Wancura, Anderson J. de Freitas, Sabrina F. Lütke, M. S. D. dos Santos, Fábio A. Mori
{"title":"Technology Advances in the Bioethanol Production from Eucalyptus Wood Biomass","authors":"Isabela de L. Valente, João H. C. Wancura, Anderson J. de Freitas, Sabrina F. Lütke, M. S. D. dos Santos, Fábio A. Mori","doi":"10.1007/s12155-023-10713-4","DOIUrl":"https://doi.org/10.1007/s12155-023-10713-4","url":null,"abstract":"","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-22DOI: 10.1007/s12155-023-10711-6
S. Ghezehei, D. Saloni
{"title":"Assessment of Feedstock Quality of Poplars (Populus L.) Using Selected Pellet-Quality Parameters","authors":"S. Ghezehei, D. Saloni","doi":"10.1007/s12155-023-10711-6","DOIUrl":"https://doi.org/10.1007/s12155-023-10711-6","url":null,"abstract":"","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138945963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-13DOI: 10.1007/s12155-023-10709-0
Italo de Andrade Bianchini, Fanny Machado Jofre, Talita Martins Lacerda, Maria das Graças de Almeida Felipe
The toxicity of hemicellulosic hydrolysates is one of the main bottlenecks of the biotechnological production of xylitol, as inhibitors released/generated during plant cell wall deconstruction impair xylitol production. Yeast adaptation can be applied to overcome this issue through the development of tolerant strains, improving microbial performance. Herein, we evaluated Candida tropicalis FTI20037 pre-cultivation in original, concentrated, and concentrated/detoxified sugarcane bagasse and straw hemicellulosic hydrolysate (SBSHH) to reduce hydrolysate’s toxicity during concentrated/detoxified SBSHH fermentations. Regarding glucose uptake, there were no differences between the evaluated conditions. In turn, lignocellulosic inhibitors negatively affected xylose uptake. The evaluated adaptive strategies did not improve xylose uptake at SBSHH fermentations. Xylitol production was also impaired by lignocellulosic inhibitors. However, pre-cultivation in concentrated/detoxified SBSHH increased xylitol yield and xylose-to-xylitol bioconversion efficiency by 13.3%, xylitol volumetric productivity by 7.1%, and xylitol specific production rate by 9.7%. A 21.5% reduction in glycerol production was also observed in this condition, indicating an increased tolerance to lignocellulosic inhibitors. Arabinose assimilation started slowly in all fermentations. Increased arabinose uptake rates were observed after xylose depletion, suggesting the existence of a carbon catabolite repression tendency between xylose and arabinose. Pre-cultivation in concentrated/detoxified SBSHH reduced this repression tendency, increasing arabinose consumption. Regarding lignocellulosic inhibitors, 5-HMF degradation was increased by pre-cultivation. No differences were observed for acetic acid and phenolic compounds consumption. The combination of SBSHH detoxification and C. tropicalis pre-cultivation was effective to improve xylitol production possibly due to the development of a more tolerant phenotype against SBSHH toxicity.
{"title":"Xylitol Production by Candida tropicalis from Sugarcane Bagasse and Straw: an Adaptive Approach to Improve Fermentative Performance","authors":"Italo de Andrade Bianchini, Fanny Machado Jofre, Talita Martins Lacerda, Maria das Graças de Almeida Felipe","doi":"10.1007/s12155-023-10709-0","DOIUrl":"https://doi.org/10.1007/s12155-023-10709-0","url":null,"abstract":"<p>The toxicity of hemicellulosic hydrolysates is one of the main bottlenecks of the biotechnological production of xylitol, as inhibitors released/generated during plant cell wall deconstruction impair xylitol production. Yeast adaptation can be applied to overcome this issue through the development of tolerant strains, improving microbial performance. Herein, we evaluated <i>Candida tropicalis</i> FTI20037 pre-cultivation in original, concentrated, and concentrated/detoxified sugarcane bagasse and straw hemicellulosic hydrolysate (SBSHH) to reduce hydrolysate’s toxicity during concentrated/detoxified SBSHH fermentations. Regarding glucose uptake, there were no differences between the evaluated conditions. In turn, lignocellulosic inhibitors negatively affected xylose uptake. The evaluated adaptive strategies did not improve xylose uptake at SBSHH fermentations. Xylitol production was also impaired by lignocellulosic inhibitors. However, pre-cultivation in concentrated/detoxified SBSHH increased xylitol yield and xylose-to-xylitol bioconversion efficiency by 13.3%, xylitol volumetric productivity by 7.1%, and xylitol specific production rate by 9.7%. A 21.5% reduction in glycerol production was also observed in this condition, indicating an increased tolerance to lignocellulosic inhibitors. Arabinose assimilation started slowly in all fermentations. Increased arabinose uptake rates were observed after xylose depletion, suggesting the existence of a carbon catabolite repression tendency between xylose and arabinose. Pre-cultivation in concentrated/detoxified SBSHH reduced this repression tendency, increasing arabinose consumption. Regarding lignocellulosic inhibitors, 5-HMF degradation was increased by pre-cultivation. No differences were observed for acetic acid and phenolic compounds consumption. The combination of SBSHH detoxification and <i>C. tropicalis</i> pre-cultivation was effective to improve xylitol production possibly due to the development of a more tolerant phenotype against SBSHH toxicity.</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138579833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-08DOI: 10.1007/s12155-023-10706-3
Joana Oliveira, Emanuel Costa, Joana Maia Dias, José C. Pires
Microalgae are lipid-rich microscopic eukaryotic algae that can be used aiming for more sustainable biodiesel production by employing environmentally sound processes. The present work evaluates biodiesel production using a biocatalyst and two microalgae species as oil feedstock (Chlorella vulgaris and Aurantiochytrium sp.). Lipid extraction was performed using different techniques, namely, Soxhlet extractions (8 h — both species) with different solvents (hexane; hexane:ethanol (1:1 v/v); and chloroform) and room temperature hexane extraction (72 h — Aurantiochytrium sp.). Transesterification occurred for 24 h (150 rpm), using 30 % lipase loading. The results showed that high extraction temperatures cause microalgae oil degradation, focused on unsaturated fatty acids, leading to a lower biodiesel conversion yield. Using Aurantiochytrium sp. oil, it was possible to obtain around 55 %wt. of biodiesel conversion yield using oil extracted at room temperature (6:1 methanol:oil molar ratio), whereas for the oil extracted in the Soxhlet apparatus, the biodiesel conversion yield was around 30 %wt.. The low lipid content (1.0 %wt.) and biodiesel conversion yield (up to 25 %wt.) obtained using C. vulgaris show that the biomass used in the current study has low potential for biodiesel production. However, enzymatic biodiesel production from microalgae represents a promising avenue for sustainable energy generation, offering a renewable and environmentally responsible solution to the world’s energy needs. For that purpose, further studies, such as the optimisation of the extraction and transesterification of Aurantiochytrium sp. oil, should be carried out.
{"title":"Biodiesel Production by Biocatalysis using Lipids Extracted from Microalgae Oil of Chlorella vulgaris and Aurantiochytrium sp.","authors":"Joana Oliveira, Emanuel Costa, Joana Maia Dias, José C. Pires","doi":"10.1007/s12155-023-10706-3","DOIUrl":"https://doi.org/10.1007/s12155-023-10706-3","url":null,"abstract":"<p>Microalgae are lipid-rich microscopic eukaryotic algae that can be used aiming for more sustainable biodiesel production by employing environmentally sound processes. The present work evaluates biodiesel production using a biocatalyst and two microalgae species as oil feedstock (<i>Chlorella vulgaris</i> and <i>Aurantiochytrium</i> sp<i>.</i>). Lipid extraction was performed using different techniques, namely, Soxhlet extractions (8 h — both species) with different solvents (hexane; hexane:ethanol (1:1 v/v); and chloroform) and room temperature hexane extraction (72 h — <i>Aurantiochytrium</i> sp.). Transesterification occurred for 24 h (150 rpm), using 30 % lipase loading. The results showed that high extraction temperatures cause microalgae oil degradation, focused on unsaturated fatty acids, leading to a lower biodiesel conversion yield. Using <i>Aurantiochytrium</i> sp. oil, it was possible to obtain around 55 %wt. of biodiesel conversion yield using oil extracted at room temperature (6:1 methanol:oil molar ratio), whereas for the oil extracted in the Soxhlet apparatus, the biodiesel conversion yield was around 30 %wt.. The low lipid content (1.0 %wt.) and biodiesel conversion yield (up to 25 %wt.) obtained using <i>C. vulgaris</i> show that the biomass used in the current study has low potential for biodiesel production. However, enzymatic biodiesel production from microalgae represents a promising avenue for sustainable energy generation, offering a renewable and environmentally responsible solution to the world’s energy needs. For that purpose, further studies, such as the optimisation of the extraction and transesterification of <i>Aurantiochytrium</i> sp. oil, should be carried out.</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138560173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-30DOI: 10.1007/s12155-023-10708-1
Samah Chaoua, Sigrid Flahaut, Serge Hiligsmann, Mehdi Mansour, Bertrand Cornu, George Songulashvili, Noreddine Kacem Chaouche
Tomato waste (TW) is a plentiful lignocellulosic resource, mainly composed of seeds and skins, that can be converted into high-value compounds. This study explored the enhancement of TW enzymatic and fungal biovalorization using novel ecofriendly approaches, including advanced technology, pulsed electric fields (PEF). Crude laccase first produced on TW was used for enzymatic treatment, and the white rot fungus Trametes versicolor K1 was used in fungal treatment under SmF (submerged) or SSF (semi-solid) fermentation conditions. The physical PEF treatment had increased tenfold sugar extraction yield (83.4 mg/g) and twofold polyphenol extraction yield (4.43 g/g), with respect to the control. PEF–laccase innovative combination, reported for the first time, has enhanced significantly sugar extraction yield (100.6 mg/g), twofold higher than those released from TW after laccase treatment alone. However, the PEF treatment had no effect on polyphenol extraction yield when combined to laccase or fungal treatments. The treated TW was subjected to polysaccharide enzymatic hydrolysis. The combination of PEF with laccase or fungal treatment did not impact sugar yields; however, it allowed polyphenol liberation. During fungal treatment (i.e., T. versicolor K1 grown on TW), comparable maximal laccase activities of 2574.28 U/L and 2577.06 U/L were measured in the culture supernatants, in SmF and SSF conditions, respectively. The findings demonstrate the high potential of PEF for recovering phenols and sugars. When combined to fungal treatment, it offers high yields of valuable products, making it a potential cost-effective approach, providing new prospects for TW valorization.
{"title":"Assessment of Green Processes for Tomato Waste Biovalorization: Spotlight on the Innovative Pulsed Electric Field–Laccase Synergy for Enhanced Sugar and Phenol Extraction Yields","authors":"Samah Chaoua, Sigrid Flahaut, Serge Hiligsmann, Mehdi Mansour, Bertrand Cornu, George Songulashvili, Noreddine Kacem Chaouche","doi":"10.1007/s12155-023-10708-1","DOIUrl":"https://doi.org/10.1007/s12155-023-10708-1","url":null,"abstract":"<p>Tomato waste (TW) is a plentiful lignocellulosic resource, mainly composed of seeds and skins, that can be converted into high-value compounds. This study explored the enhancement of TW enzymatic and fungal biovalorization using novel ecofriendly approaches, including advanced technology, pulsed electric fields (PEF). Crude laccase first produced on TW was used for enzymatic treatment, and the white rot fungus <i>Trametes versicolor</i> K1 was used in fungal treatment under SmF (submerged) or SSF (semi-solid) fermentation conditions. The physical PEF treatment had increased tenfold sugar extraction yield (83.4 mg/g) and twofold polyphenol extraction yield (4.43 g/g), with respect to the control. PEF–laccase innovative combination, reported for the first time, has enhanced significantly sugar extraction yield (100.6 mg/g), twofold higher than those released from TW after laccase treatment alone. However, the PEF treatment had no effect on polyphenol extraction yield when combined to laccase or fungal treatments. The treated TW was subjected to polysaccharide enzymatic hydrolysis. The combination of PEF with laccase or fungal treatment did not impact sugar yields; however, it allowed polyphenol liberation. During fungal treatment (i.e., <i>T. versicolor</i> K1 grown on TW), comparable maximal laccase activities of 2574.28 U/L and 2577.06 U/L were measured in the culture supernatants, in SmF and SSF conditions, respectively. The findings demonstrate the high potential of PEF for recovering phenols and sugars. When combined to fungal treatment, it offers high yields of valuable products, making it a potential cost-effective approach, providing new prospects for TW valorization.</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138517781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-30DOI: 10.1007/s12155-023-10702-7
Wasu Suksuwan, Arkom Palamanit, Makatar Wae-hayee
This study investigated the behavior and syngas characteristics of oil palm biomass fluidized bed gasification (FBG) with alternative inlet air configurations. The air was supplied to the combustion zone of the FBG with tangential and updraft air inlet (TI and UI) modes. A mixed oil palm decanter cake was used as feedstock at 3 kg/h feed rate. The experiments were done at the equivalence ratios (ERs) from 0.1 to 1.0. The experimental results showed that the air supply mode and ER affected the temperature distribution inside the gasifier. Operation with TI mode had combustion initiated at the side, then propagated through the middle section, while in UI mode, the combustion reaction was at the center of the chamber. With TI mode, the temperature at combustion zone was around 600 °C. At ER 0.5, this zone covered the heights from 0.25 to 0.75 m. In UI mode, the highest temperature was near 800 °C, but combustion was prominent only in a zone near the bottom. The CFD simulations showed that the alternative inlet air configurations and the ER influenced flow patterns. CFD confirmed the swirling streamlines in TI mode, while UI mode showed a localized elevated temperature, particularly at 0.25 m height. Syngas composition analysis indicated that operation in TI mode at ER of 0.7 provided the larger combustion zone, leading to better syngas product in terms of CO (> 20%) and H2 (> 8%) components. This mode also provided the best 5.1 MJ/m3 energy content for syngas. The results of this study can provide useful guidelines for further investigations of FBG with tangential air inlet.
{"title":"Behavior and Syngas Characteristics with Alternative Inlet Air Configurations in Fluidized Bed Gasification of Oil Palm Biomass","authors":"Wasu Suksuwan, Arkom Palamanit, Makatar Wae-hayee","doi":"10.1007/s12155-023-10702-7","DOIUrl":"https://doi.org/10.1007/s12155-023-10702-7","url":null,"abstract":"<p>This study investigated the behavior and syngas characteristics of oil palm biomass fluidized bed gasification (FBG) with alternative inlet air configurations. The air was supplied to the combustion zone of the FBG with tangential and updraft air inlet (TI and UI) modes. A mixed oil palm decanter cake was used as feedstock at 3 kg/h feed rate. The experiments were done at the equivalence ratios (ERs) from 0.1 to 1.0. The experimental results showed that the air supply mode and ER affected the temperature distribution inside the gasifier. Operation with TI mode had combustion initiated at the side, then propagated through the middle section, while in UI mode, the combustion reaction was at the center of the chamber. With TI mode, the temperature at combustion zone was around 600 °C. At ER 0.5, this zone covered the heights from 0.25 to 0.75 m. In UI mode, the highest temperature was near 800 °C, but combustion was prominent only in a zone near the bottom. The CFD simulations showed that the alternative inlet air configurations and the ER influenced flow patterns. CFD confirmed the swirling streamlines in TI mode, while UI mode showed a localized elevated temperature, particularly at 0.25 m height. Syngas composition analysis indicated that operation in TI mode at ER of 0.7 provided the larger combustion zone, leading to better syngas product in terms of CO (> 20%) and H<sub>2</sub> (> 8%) components. This mode also provided the best 5.1 MJ/m<sup>3</sup> energy content for syngas. The results of this study can provide useful guidelines for further investigations of FBG with tangential air inlet.</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138517791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development and use of renewable energy resources is a crucial solution for a sustainable energy strategy to decrease the dependence on fossil fuels. Lignocellulosic ethanol has gained recognition as a renewable energy resource vital for sustainable development. Currently, the research and industry sectors utilize a single type of lignocellulose biomass for ethanol production. However, this biomass dependency is a potential risk due to the global warming effect on biomass plantations. This study assessed the versatility of rice straw (RS), Napier grass (NG), and sugarcane bagasse (SB) as a mixed biomass for bioethanol production. The mixture of equal proportion of RS, NG, and SB in a 1:1:1 ratio produced higher concentration of bioethanol than individual biomasses. NaOH-pretreated samples were more effective than H2SO4 pretreated and untreated samples in bioethanol production. The NaOH-pretreated mixed sample yielded maximum bioethanol of 0.82% (v/v). About 0.43 g/g and 0.12 g/g of reducing sugars and ethanol, respectively, could be produced using RS, NG, and SB in the ratio of 1:1:1. This research indicates that different biomass types can replace one another in the event of limited resources, thus reducing the dependency on a particular biomass type for biorefinery.
{"title":"The Versatility of Mixed Lignocellulose Feedstocks for Bioethanol Production: an Experimental Study and Empirical Prediction","authors":"Kraipat Cheenkachorn, Richard Q. Mensah, Babu Dharmalingam, Marttin Paulraj Gundupalli, Kittipong Rattanaporn, Prapakorn Tantayotai, Pau Loke Show, Malinee Sriariyanun","doi":"10.1007/s12155-023-10705-4","DOIUrl":"https://doi.org/10.1007/s12155-023-10705-4","url":null,"abstract":"<p>The development and use of renewable energy resources is a crucial solution for a sustainable energy strategy to decrease the dependence on fossil fuels. Lignocellulosic ethanol has gained recognition as a renewable energy resource vital for sustainable development. Currently, the research and industry sectors utilize a single type of lignocellulose biomass for ethanol production. However, this biomass dependency is a potential risk due to the global warming effect on biomass plantations. This study assessed the versatility of rice straw (RS), Napier grass (NG), and sugarcane bagasse (SB) as a mixed biomass for bioethanol production. The mixture of equal proportion of RS, NG, and SB in a 1:1:1 ratio produced higher concentration of bioethanol than individual biomasses. NaOH-pretreated samples were more effective than H<sub>2</sub>SO<sub>4</sub> pretreated and untreated samples in bioethanol production. The NaOH-pretreated mixed sample yielded maximum bioethanol of 0.82% (v/v). About 0.43 g/g and 0.12 g/g of reducing sugars and ethanol, respectively, could be produced using RS, NG, and SB in the ratio of 1:1:1. This research indicates that different biomass types can replace one another in the event of limited resources, thus reducing the dependency on a particular biomass type for biorefinery.</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138517793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrogen, a form of energy that is both clean and renewable, is now being researched and developed as a potential source of alternative energy. There are many different kinds of microbial systems that have the potential to be utilised in the manufacturing of biohydrogen. Thermophiles are found as potential producers of hydrogen, at a high rate, in adverse operating conditions. Temperature, pH, and concentration of substrates play a crucial role in affecting the metabolism of these microorganisms. Sustainable production of hydrogen is feasible when organic waste is employed as a potential feedstock. The overall yield of hydrogen production procedures demands improvements, to turn them into commercial applications. The integration of two-stage processes may contribute to an overall increase in energy output. As examples of second-stage processes, biomethanation, microbial electrolysis cells, photo-fermentation, and microbial fuel cells have been the subject of extensive research. This article provides an overview of the photocatalytic method for producing biohydrogen, including its fundamentals and underlying mechanisms, as well as other biological methods of hydrogen production. This process exhibits reduced energy consumption and demonstrates environmental friendliness by potentially utilising waste material as a substrate.