Application In Biofuel Production Research Articles

Heterologous expression and characterization of a MoAA16 polysaccharide monooxygenase from the rice blast fungus Magnaporthe oryzae

BackgroundCellulose is an organic carbon source that can be used as a sustainable alternative for energy, materials, and chemicals. However, the substantial challenge of converting it into soluble sugars remains a major obstacle in its use as a biofuel and chemical feedstock. A new class of enzymes knowns as copper-dependent polysaccharide monooxygenases (PMOs) or lytic polysaccharide monooxygenases (LPMOs) can break down polysaccharides such as cellulose, chitin, and starch through oxidation. This process enhances the efficiency of cellulose degradation by cellulase. ResultsThe genome of the fungus Magnaporthe oryzae, the causal agent of rice blast disease, contains the MGG_00245 gene, which encodes a putative PMO referred to as MoAA16. MoAA16 has been found to be highly expressed in planta during the early stages of fungal infection. The gene was optimized for heterologous expression in Pichia pastoris, and its oxidative cleavage activity on cellulose was characterized by analyzing soluble oligosaccharide products using highperformance anion exchange chromatography (HPAEC-PAD). The reaction catalyzed by MoAA16 requires 2 electrons from an electron donor, such as ascorbic acid, and aerobic conditions. It primarily produces Glc1 to Glc4 oligosaccharides, as well as oxidized cellobionic and cellotrionic acids. MoAA16 has been observed to enhance cellulase hydrolysis on phosphoric acid swollen cellulose (PASC) substrate, resulting in the production of more monosaccharide products. ConclusionsOur findings reveal the successful heterologous expression of MoAA16 in P. pastoris and its cellulose-active PMO properties. These results highlight the potential of MoAA16 as a promising candidate for applications in biofuel production and chemical synthesis.How to cite: Nguyen HM, Le LQ, Sella L, et al. Heterologous expression and characterization of a MoAA16 polysaccharide monooxygenase from the rice blast fungus Magnaporthe oryzae. Electron J Biotechnol 2023. https://doi.org/10.1016/j.ejbt.2023.06.002.

Advancing Process Intensification with High-Frequency Ultrasound: A Mini-Review of Applications in Biofuel Production and Beyond

High-frequency ultrasound (HFU) is an ultrasound technology with a frequency higher than 1000 kHz. It has become increasingly recognized as an emerging process intensification technology in various fields, such as biofuel production, carbon dioxide absorption, and wastewater treatment. HFU is seen as a potential intensifier technology for biofuel production, as its mechanisms, such as cavitational phenomena, microstreaming, and fountain formation, can benefit biofuel production. Previous research has shown that HFU can decrease the reaction time required for biofuel production, aid in lipid extraction, increase carbon dioxide absorption rates, and be effective in destroying pathogens in wastewater treatment. However, despite the potential benefits, there are limited reports on the use of HFU technology for biofuel production, which has led to uncertainties and constraints in its industrial deployment. These constraints include equipment design, economic analysis, and safety concerns, which require further in-depth analysis. Despite these limitations, previous studies have shown promising results for the incorporation of HFU into various fields due to its unique characteristics and mechanisms. This paper presents a review of the theory and application of HFU for process intensification, with a focus on its potential for biofuel production. It also provides recommendations for the further exploration of the technology to overcome industrial deployment obstacles.

Ecological landscapes guide the assembly of optimal microbial communities.

Assembling optimal microbial communities is key for various applications in biofuel production, agriculture, and human health. Finding the optimal community is challenging because the number of possible communities grows exponentially with the number of species, and so an exhaustive search cannot be performed even for a dozen species. A heuristic search that improves community function by adding or removing one species at a time is more practical, but it is unknown whether this strategy can discover an optimal or nearly optimal community. Using consumer-resource models with and without cross-feeding, we investigate how the efficacy of search depends on the distribution of resources, niche overlap, cross-feeding, and other aspects of community ecology. We show that search efficacy is determined by the ruggedness of the appropriately-defined ecological landscape. We identify specific ruggedness measures that are both predictive of search performance and robust to noise and low sampling density. The feasibility of our approach is demonstrated using experimental data from a soil microbial community. Overall, our results establish the conditions necessary for the success of the heuristic search and provide concrete design principles for building high-performing microbial consortia.

Microalgae Cultures: Environmental Tool and Bioenergy

Microalgae have been intensively studied for CO2 capture, nutrient removal from wastewater, and biofuel production applications [...]

Enhanced interfacial electron transfer between semiconductor and non-photosynthetic microorganism under visible light

Under visible light, non-photosynthetic microorganism/semiconductor has recently shown promising applications in biofuel production, bioenergy generation and pollutant removal. However, the understanding of electron transfer mechanism at the biotic-abiotic interface is limited. Herein, mixed culture/carbon nitride and pure culture (Stenotrophomonas maltophilia HP14)/carbon nitride were constructed to reveal the energy conversion pathway under visible light. Enhanced electron transfer was observed on the biotic-abiotic interface. The photocurrent of non-photosynthetic S. maltophilia HP14/g-C3N4/ITO with riboflavin addition was 10.2-fold higher than that of g-C3N4/ITO control. As the electron donor, S. maltophilia HP14 transfer bio-electrons to self-secreted riboflavin and valence band of semiconductor. Riboflavin (RF) accept bio-electrons and photogenerated electrons to form 1,5-dihydroflavin (RFH2). While RFH2 is able to transfer electrons to the valence band of carbon nitride and transform into RF again. However, riboflavin is not stable under visible light irradiation, which may lead to a decreased photocurrent. This study demonstrated the role of redox active compounds at the microorganism/semiconductor interface and described a possibility for non-photosynthetic microorganisms to capture and utilize visible light.

ULTRASONIC DISINTEGRATION OF LIGNOCELLULOSE RAW MATERIALS AS A PRE-TREATMENT OF A SUBSTRATE FOR MICROBIOLOGICAL PRODUCTION OF BIOBUTANOL

Aim. The purpose of the study was to investigate the effect of ultrasonic disintegration on the lignocellulosic raw materials (biomass of the non-cereal part of rape) with its subsequent use as a substrate for the production of biobutanol. Methods. Butanol-producing strains and the biomass of the non-cereal part of rape Brassica napus were used in the present study. Ultrasonic disintegration of lignocellulosic raw materials was performed on the specially designed equipment. Results. The effect of ultrasonic disintegration on lignocellulosic raw materials was investigated for further application in biofuel production based on microbiological conversion. The possibility of using the obtained components after the pre-treatment of lignocellulose by ultrasonic disintegration as a substrate for the microbiological synthesis of butanol was shown. The highest accumulation of butanol (2.4 g/l) was obtained with the use of 5% dry matter content in the medium, 5 min treatment and the specific power of ultrasonic disintegration of 0.72 W/ml. Conclusions. The possibility of producer strains of the genus Clostridium to use cellulose in the fermentation process has been shown. When using ultrasonic disintegration for pretreatment of the non-cereal part of the biomass of rape, the accumulation of butanol increased by 3 folds.

Feruloyl esterase Fae1 is required specifically for host colonisation by the rice-blast fungus Magnaporthe oryzae.

Plant cell wall acts as a primary barrier for microbial pathogens during infection. A cell wall-degrading enzyme thus may be a crucial virulence factor, as it may aid the pathogen in successful host invasion. Nine genes coding for feruloyl esterases (Fae), likely involved in plant cell wall degradation, have been annotated in the genome of the cereal-blast fungus Magnaporthe oryzae. However, role of anyFae in pathogenicity of M. oryzae remains hitherto under explored. Here, we identified FAE1 gene (MGG_08737) that was significantly upregulated during host penetration and subsequent colonisation stages of infection. Accordingly, while deletion of FAE1 in M. oryzae did not affect the vegetative growth and asexual development, the fae1Δ mutant showed significantly reduced pathogenesis on rice plants, mainly due to impaired host invasion and colonisation. Very few (< 10%) fae1Δ appressoria that formed the primary invasive hyphae failed to elaborate from the first invaded cell to the neighbouring plant cells. Interestingly, exogenously added glucose, as a simple carbon source, or ferulic acid, a product of theFae activity, significantly supported the invasive growth of the fae1Δ mutant. We show that the Fae1-based feruloyl esterase activity, by targeting the plant cell wall, plays an important role in accumulating ferulic acid and/or sugar molecules, as a likely energy source, to enable host invasion and colonisation by M. oryzae. Given its role in plant cell wall digestion and host colonisation, M. oryzae Fae1 could be a potential candidate for a novel antifungal strategy and a biotechnological application in biofuel production.

Phycoremediation: Heavy Metals Green-Removal by Microalgae and Its Application in Biofuel Production

Heavy metals are non-degradable pollutants. Heavy metals accumulation in the environment increases along with the massive industrial activity and the growth of the human population. These pollutants are hazardous to various kinds of living things. The accumulation of heavy metals in the environment triggers bioaccumulation and biomagnification. Heavy metal exposure causes some health problems in humans. The conventional methods of heavy metals adsorption are less effective, expensive, and cause other problems. Phycoremediation using microalgae is a promising alternative method for absorbing heavy metals. Microalgal cells consist of various components such as lipids, polysaccharides, and proteins. Those compounds contain negative charges that will interact with positive charges on heavy metals. The bond between these different charges leads to the adsorption of heavy metals in the environment to the surface of microalgal cells. In this review, the authors discussed the potential use of microalgae to adsorb heavy metals polluting the environment. Phycoremediation is cheaper, easier, and safer for the environment. Besides, the microalgal biomass can be utilized in biofuel production

Evaluation of African Star Apple (Chrysophyllum albidum) Seed Oil as a Potential Feedstock for Industrial Application

Aims: Evaluate possible application of African Star Apple seed oil as industrial raw material geared towards possible conversion of waste to wealth with no negative impact as it borders on food scarcity. Also unveiling the possibility of a sustainable environment via the eradication of waste from the environment, thereby creating a clean environment.&#x0D; Place and Duration of Study: Fresh ripped fruits of African Star Apple were bought from some local market sellers at Agbarha-Otor market which is located in Ughelli North Local Government Area of Delta State, Nigeria on longitude 6° 2' 54" E /5° 30' 40" N, between November, 2019 and March, 2020.&#x0D; Experimental Details: Soxhlet extraction with n-hexane as solvent was used for the oil extraction of 100 g per batch of extraction. Pretreatment procedure of oil was done prior to transesterification. Homogenous base-catalyzed transesterification reaction was used in this study under controlled experimental conditions such as temperature, reaction time, methanol to oil molar ratio and catalyst type and concentration were examined under varied ranges to ascertain optimum experimental conditions for the reaction. Extracted seeds oil were analysed for its physicochemical properties using standard methods via: specific gravity, acid value, refractive index, saponification value, iodine value and free fatty acid using standard methods.&#x0D; Results: The results showed an oil yield of 14.9%, an indication that the seed reflects a poor source of abundant oil. Results obtained for the physiochemical properties, revealed that; specific gravity, refractive index, saponification value, acid value, free fatty acid and iodine value showed values of 0.896 kg/m3, 1.549, 231.32 mgKOH/g, 3.23 mgKOH/g, 2.07% and 47.63 mg/100 g respectively. Also, results for Methanol: Oil ratio showed that maximum yield was obtained at 6:1 molar ratio. Maximum conversion efficiency for molar concentration was achieved at 0.75% for both catalysts. While a reaction time of 125 min projected better yield.&#x0D; Conclusion: The seed of African star fruit are discarded as waste, therefore its use as a source of oil for industrial feedstock and other domestic application, poses no challenge with regards to food security. Its non-drying potential based on its low iodine value, makes it suitable lubricating oil for industrial application. Similarly, potential application of the oil as feedstock for the production of biodiesel is justified on the basis of its low acid value. Conclusively, the seeds may not have sufficient oil volume potential to be used as edible (domestic) and industrial oil. Consequently upon its low yield, application for biofuel production in commercial scale becomes unrealistic.

N-Butanol production by Saccharomyces cerevisiae from protein-rich agro-industrial by-products.

n-Butanol is a renewable resource with a wide range of applications. Its physicochemical properties make it a potential substitute for gasoline. Saccharomyces cerevisiae can produce n-butanol via amino acid catabolic pathways, but the use of pure amino acids is economically unfeasible for large-scale production. The aim of this study was to optimize the production of n-butanol by S. cerevisiae from protein-rich agro-industrial by-products (sunflower and poultry offal meals). By-products were characterized according to their total protein and free amino acid contents and subjected to enzymatic hydrolysis. Protein hydrolysates were used as nitrogen sources for the production of n-butanol by S. cerevisiae, but only poultry offal meal hydrolysate (POMH) afforded detectable levels of n-butanol. Under optimized conditions (carbon/nitrogen ratio of 2 and working volume of 60%), 59.94mg/L of n-butanol was produced using POMH and glucose as substrates. The low-cost agro-industrial by-product showed great potential to be used in the production of n-butanol by S. cerevisiae. Other protein-rich residues may also find application in biofuel production by yeasts.

Valorization of food waste: Extraction of cellulose, lignin and their application in energy use and water treatment

The study focuses on the isolation of the two important macromolecules of plant, lignin, and cellulose microcrystals (CMC) from agro-waste (peanut shell) and evaluates their potential application in biofuel production and wastewater treatment. The extraction of CMC was a two-step pretreatment process carried out by utilizing Sodium hydroxide followed by bleaching with Sodium Hypochlorite. The result showed that about 0.39 g/g of cellulose (dry wt%) was extracted from peanut shell waste. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction were considered for the characterization of cellulose and lignin. Also, besides, the saccharification and fermentation process was optimized. The maximum yield of reducing sugar was 3.16 mg/ml at pH (7) utilizing cellulose (5gm). A significant difference in bioethanol yield was observed between Zymomonas mobilis and Saccharomyces cerevisiae producing (0.471 g/g) and (0.637 g/g) bioethanol respectively. The Kraft lignin (1.5 mg/ml) and cellulose left after bioethanol extraction (CLA) were further used for crystal violet dye removal. The maximum adsorption capacity shown by lignin was about 87.64% followed by cellulose with 69% removal, whereas for CLA the removal capacity was highest to 98.21%. The finding demonstrates the potential of extracted cellulose for bioethanol production, and the challenges of utilizing CLA and lignin in wastewater treatment.

Multicopper oxidases: modular structure, sequence space, and evolutionary relationships.

Multicopper oxidases (MCOs) use copper ions as cofactors to oxidize a variety of substrates while reducing oxygen to water. MCOs have been identified in various taxa, with notable occurrences in fungi. The role of these fungal MCOs in lignin degradation sparked an interest due to their potential for application in biofuel production and various other industries. MCOs consist of different protein domains, which led to their classification into two-, three-, and six-domain MCOs. The previously established Laccase and Multicopper Oxidase Engineering Database (https://lcced.biocatnet.de) was updated and now includes 51 058 sequences and 229 structures of MCOs. Sequences and structures of all MCOs were systematically compared. All MCOs consist of cupredoxin-like domains. Two-domain MCOs are formed by the N- and C-terminal domain (domain N and C), while three-domain MCOs have an additional domain (M) in between, homologous to domain C. The six-domain MCOs consist of alternating domains N and C, each three times. Two standard numbering schemes were developed for the copper-binding domains N and C, which facilitated the identification of conserved positions and a comparison to previously reported results from mutagenesis studies. Two sequence motifs for the copper binding sites were identified per domain. Their modularity, depending on the placement of the T1-copper binding site, was demonstrated. Protein sequence networks showed relationships between two- and three-domain MCOs, allowing for family-specific annotation and inference of evolutionary relationships.

Functional expression and characterization of an endo-1,4-β-mannosidase from Triticum aestivum in Pichia pastoris

Endo-1,4-β-mannosidases catalyze the cleavage of the β-d-1,4-mannopyranosyl linkage in mannan and have potential biotechnological applications in biofuel production, manno-oligosaccharide production, cleansing, and food and feed industries. In this study, an endo-1,4-β-mannosidase gene (TaMan3A) from wheat (Triticum aestivum) was successfully expressed in Pichia pastoris, and the antifungal effectiveness and manno-oligosaccharide production of the enzyme were evaluated. The purified TaMan3A exhibited a molecular weight of approximately 43 kDa, and its highest enzyme activity at pH 4.0 and 40 °C. Comparisons with other β-mannanases showed that TaMan3A had a conserved mannan-binding V-shaped groove, catalytic acid/base residue (E179), and nucleophilic residue (E297). Antifungal assays for TaMan3A against seven fungi commonly associated with wheat kernels showed that this enzyme had higher inhibitory effects on hyphal growth of the field fungi Fusarium graminearum and Alternaria sp. in comparison with that of storage fungi. TaMan3A could hydrolyze mannan polymers of galactomannan and Konjac glucomannan to mannobiose, mannotriose, and mannotetraose as the main products. Overall, these results showed the potential of TaMan3A for enhancing host resistance against fungal pathogens in wheat and manno-oligosaccharide production in the feed and food industries.

The production of polyhydroxyalkanoate from waste cooking oil and its application in biofuel production

This research presents an approach for using waste cooking oil as a substrate for the production of polyhydroxyalkanoate (PHA) by Bacillus thermoamylovorans. In addition, PHA was utilised as a feedstock for a biofuel, namely 3-hydroxyalkanoate methyl ester (3HAME). The largest amount of biomass (4.0 ± 0.1 g/L) and the greatest production of PHA [3.5 ± 0.1 g/L, corresponding to 87.5% of cell dry mass (CDM)] were obtained under optimal conditions, with 4% (w/v) waste cooking oil (WCO) used as a carbon source at 45 °C and 150 rpm for 48 h under batch cultivation. The isolated polymer was identified as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] with 85 mol% of 3-hydroxybutyrate (3HB) and 15 mol% of 3-hydroxyvalerate (3HV) using gas chromatography–mass spectrometry (GC–MS). Notably, the properties of the copolymer were similar to the properties of the commercial P(3HB-co-3HV). Moreover, P(3HB-co-3HV) was used as a feedstock for the biofuel. P(3HB-co-3HV) methyl ester, a biofuel, was obtained under optimal conditions, with methanol and 15% (v/v) H2SO4 under a reaction temperature of 65 °C and time of 60 h. The highest yield of 3HAME that was obtained was 74.4%, with 97% methyl ester content. Almost all of the properties of 3HAME pass ASTM and Thailand’s fuel standards.

Nano-immobilized cellulases for biomass processing with application in biofuel production.

Several researches have focused on the enzymatic pretreatment of lignocellulose biomass to produce fermentable sugars that can lead to ethanol production thus facilitating pathways for sustainable biofuel production. Enzymes are fundamental to the pretreatment process, however, are required in larger quantities during pretreatment process thus influencing biofuel production cost. Immobilization of enzymes to a suitable support/matrix could enhance its stability, and reusability thus containing cost. This chapter focuses on developing an advanced technology for immobilizing enzymes to nanomaterials; variety of nanomaterials used for immobilization, nature of enzyme/protein nanomaterial interactions, methods of enzyme immobilization, and factors affecting mode of interaction for achieving hydrolysis of microcrystalline cellulose and natural cellulosic substrate. The binding of enzyme (94%) to a nanomaterial was established by spectroscopy techniques. The kinetics study, conducted at optimum pH (pH 4) and temperature (50°C for free and 60°C immobilized enzyme), exhibited improvement in immobilized enzyme properties. The immobilized enzyme retained up to 50% of its enzyme activity in five consecutive cycles. This chapter advocates the use of nano-immobilized enzymes in biomass hydrolysis for biofuel production.

Directed in vitro evolution of bacterial expansin BsEXLX1 for higher cellulose binding and its consequences for plant cell wall-loosening activities.

Expansins are cell wall-loosening proteins found in all land plants and many microbial species. Despite homologous structures, bacterial expansins have much weaker cellulose binding and wall-loosening activity than plant expansins. We hypothesized stronger cellulose binding would result in greater wall-loosening activity and used invitro evolution of Bacillus subtilis BsEXLX1 to test this hypothesis. Mutants with stronger binding generally had greater wall-loosening activity, but the relationship was nonlinear and plateaued at ~40% higher than wild-type. Mutant E191K exhibited stronger cellulose binding but failed to induce creep, evidently due to protein mistargeting. These results reveal the complexity of interactions between plant cell walls and wall-modifying proteins, an important consideration when engineering proteins for applications in biofuel production and plant pathogen resistance.

Lignocellulosic biofuel production: review of alternatives

Global environmental protection is of immediate concern that can only be achieved by avoiding the use of fossil fuels and tailpipe emissions. In addition, investment on waste disposal is not economical; however, recycling of the same waste for renewable energy production is favorable in the economic and social development of the society in an eco-friendly manner. Utilization of biodegradable wastes, such as agricultural and forestry residues, and non-edible plant matter for value-added bioproducts is a promising, inexpensive, and abundant clean substitute of fossil fuels. There has been extensive research on the conversion of lignocellulosic materials to biofuels over the past few decades. The recalcitrance of lignin in crop residues, however, impedes polysaccharide accessibility and its transformation into commercially significant choice of value-added products. Traditional physiochemical and thermal methods are hampered by high-cost processing steps in pretreatment and saccharification, and also require additional maintenance and care due to the generation of eco-unfriendly compounds. Recent advances in novel consolidated bioprocessing through mixed consortium are promising choices to reduce both the number of operational steps and the production of inhibitors with higher conversion efficiency. Although biofilm-based technologies have been successfully applied for wastewater and solid waste treatment, their potential application in biofuel production has been unexplored. The present review focuses on the state-of-the-art development of biofuel production by mixed consortium and also recent strategies to improve biofuel yield including the metabolic pathway construction.

Characterization of sulfur-compound metabolism underlying wax-ester fermentation in Euglena gracilis

Euglena gracilis is a microalga, which has been used as a model organism for decades. Recent technological advances have enabled mass cultivation of this species for industrial applications such as feedstock in nutritional foods and cosmetics. E. gracilis degrades its storage polysaccharide (paramylon) under hypoxic conditions for energy acquisition by an oxygen-independent process and accumulates high amount of wax-ester as a by-product. Using this sequence of reactions referred to as wax-ester fermentation, E. gracilis is studied for its application in biofuel production. Although the wax-ester production pathway is well characterized, little is known regarding the biochemical reactions underlying the main metabolic route, especially, the existence of an unknown sulfur-compound metabolism implied by the nasty odor generation accompanying the wax-ester fermentation. In this study, we show sulfur-metabolomics of E. gracilis in aerobic and hypoxic conditions, to reveal the biochemical reactions that occur during wax-ester synthesis. Our results helped us in identifying hydrogen sulfide (H2S) as the nasty odor-producing component in wax-ester fermentation. In addition, the results indicate that glutathione and protein degrades during hypoxia, whereas cysteine, methionine, and their metabolites increase in the cells. This indicates that this shift of abundance in sulfur compounds is the cause of H2S synthesis.

Facile production of biofuel via solvent-free deoxygenation of oleic acid using a CoMo catalyst

Support- and sulfide-free cobalt molybdenum catalysts are prepared via different synthetic procedures for catalytic deoxygenation of oleic acid under inert (N2) and solvent-free conditions. Among the tested catalysts, the CoMo catalyst prepared via a sol-gel method achieves the highest catalytic performance, namely, 88.9% oleic acid conversion, with 48.1% C9–C17 selectivity, and 69.6% oxygen removal rate, owing to its excellent physical properties. Additionally, oxygen vacancy is formed in CoMo catalyst during sol-gel synthesis process and it also effect on the catalytic activity. Examination of the deoxygenation reaction over pre-reduced catalysts reveals that the CoMoO4 species is the active species in the CoMo catalysts. The fuel properties of the resultant products are affected strongly by the catalytic performances of the CoMo catalysts. The biofuel produced using the CoMo catalyst prepared via the sol-gel method showed the highest calorific value (10,119 cal/g) and the lowest viscosity (31.5 cP), and, consequently, this CoMo catalyst exhibits the highest catalytic activity and has significant potential for application in biofuel production.

Synthesis, characterization, and catalytic properties of the Li-doped ZnO

In this study, attention was directed at the interactions between Li-doped ZnO systems and rye cereal. The interaction of cereal grains and straws with the transition metal ions is of biochemical importance primarily due to the presence of those complexes in biological systems. Metal/cereal chemistry plays a crucial role in the cross-linking of various biomolecules, and formed systems seem to be promising for various applications, such as material for the production of carbonizate and gaseous substances, which allows for the preparation of second generation biofuels. In the study of cereal/metal complexes, thermogravimetric measurements were performed in order to explain the influence of ZnO and Li2xZn1−xO oxides on the thermal decomposition of rye grains in relation to their application for biofuel production. The possibility of generation of volatile products and carbonizate was considered. The characterization of carbonizate and volatile products was made. The catalytic properties of Li2xZn1−xO phases in the decomposition of cereal grains were confirmed through thermal analysis. The thermal degradation of rye grains was catalyzed by Li-doped ZnO systems. Superior degradation to volatile products depended upon both the botanical origin of the cereal and the catalyzing system.