Selected highlights of scientific publications, technology developments and partnerships.

SCIENCE

Xyloglucan processing machinery in Xanthomonas pathogens and its role in the transcriptional activation of virulence factors

JUL-2021 Among the hemicellulose polysaccharides, xyloglucan is a significant fraction in most terrestrial plants, with great biotechnological potential. The bacteria Xanthomonas possess dozens of enzymes that degrade different polysaccharides, and this paper describes the discovery of a family of enzymes, a carbohydrate esterase (CE20), which is one of the links in the xyloglucan depolymerization and uptake machinery. Normally sugars are carbon sources for microorganisms, but in this case, the bacterium went further, using the sugars from xyloglucan depolymerization as inducers of protein expression that assist the microorganism to break the cell wall and modulate the plant’s natural defense mechanisms.

SCIENCE

Implications of regional N2O–N emission factors on sugarcane ethanol emissions and granted decarbonization certificates

JUL-2021 Nitrous oxide (N2O) emissions from N fertilizers are the main sources of greenhouse gases (GHG) emitted from sugarcane ethanol. This study derived regional N2O emission factors (EFs) from N fertilizers and evaluated how the use of such EFs affects ethanol emissions and the earning of decarbonization certificates (CBIOs). Regional N2O EFs reduced by 19% the GHG emissions from sugarcane ethanol compared with those using the IPCC default value. Regional-specific data provide more realistic indicators to account for GHG emissions of sugarcane ethanol and generate economic benefits with extra CBIOs for biofuel producers.

SCIENCE

Sustainability analysis of bioethanol production in Mexico by a retrofitted sugarcane industry based on the Brazilian expertise

JUL-2021 In 2012, Mexico began a transition to the use of renewable energy with the strategy of adopting a 10% blend of ethanol in gasoline, with an estimated annual demand of 3 billion liters to be produced mainly from sugarcane. This article analyzes how it is possible to use part of the experience acquired by Brazil during its transition from sugar mills to advanced biorefineries for the Mexican case, presenting technical-economic, social, and environmental analysis for retrofit scenarios of Mexican sugar mills.

SCIENCE

C4 Bacterial Volatiles Improve Plant Health

JUN-2021 The search for sustainable agriculture also involves the study of microorganisms with the potential to improve plant growth and health. This review involves small metabolites produced by bacteria, the bacterial volatile compounds (BVC), that are able to activate the plant immune system, to promote plant growth and to act as biological control agents. The review also covers the positive action of BVC-conjugant on plants and the potential of some BVC as substrate for production of bioproducts.

SCIENCE

Inorganics in sugarcane bagasse and straw and their impacts for bioenergy and biorefining: A review

JUN-2021 Valorization of sugarcane bagasse and straw has been hampered by the quality of these biomasses, mainly regarding their inorganic content. This paper reviews the types of inorganics and their variability, and the impacts of inorganics in several biorefinery processes and products. In the article’s view, understanding the role of inorganics is key for the design of biorefineries of grasses such as sugarcane.

SCIENCE

How do nitrogen fertilization and cover crop influence soil C-N stocks and subsequent yields of sugarcane?

APR-2021 Legumes fix nitrogen (N) from the atmosphere, making them excellent options for providing N to the agricultural system and indirectly mitigating greenhouse gas emissions by reducing the demand for synthetic fertilizers. Sugarcane cultivation requires N, but there are no reports of the impacts of its cultivation on C-N stocks. This paper proved that nitrogen fertilization and crop rotation with legumes increased sugarcane yield by 12%, increased N stocks and soil microbial biomass, but did not affect soil carbon (C) stocks.

SCIENCE

Multilocation changes in soil carbon stocks from sugarcane straw removal for bioenergy production in Brazil

APR-2021 The soil is the main carbon (C) pool of the terrestrial ecosystem and, depending on the land use, it can act as a source or drain of atmospheric CO2. The sugarcane straw is an important C input for soils and also has a high potential for bioenergy production. This study evaluated the impacts of straw removal on soil C stocks under different soil and climate conditions in Brazil. It has been confirmed that excessive straw removal decreases soil C stocks, and these impacts are more negative on sandy soils. It is concluded that the adverse impacts on the soil must be included in life cycle assessment of bioenergy produced from straw.

SCIENCE

Electrostatic Interactions Optimization Improves Catalytic Rates and Thermotolerance on Xylanases

APR-2021 Designing enzymes with more sophisticated catalytic machineries than those found in nature streamline the generation of new enzymes and its use for diverse biotechnological applications. This work describes a novel and efficient computation-guided method capable of rationally ‘customizing’ enzymes with improved catalytic rates and thermotolerance. This new technology has potential impact on the development of industrially relevant products.

SCIENCE

Structure of the class XI myosin globular tail reveals evolutionary hallmarks for cargo recognition in plants

APR-2021 Understanding the molecular mechanisms for the transport of cellular components is important in the production of biorenewables, as they are involved from the secretion of fungal enzyme to plant growth. This work unveils the high-resolution structure of an important protein domain that determines what type of components will be transported by the molecular motor myosin. The work also applied a new method of experimental phasing based on libraries of short fragments, which broadened the spectrum of experimental approaches to elucidate new protein structures.

SCIENCE

Identifying suitable areas for expanding sugarcane ethanol production in Brazil under conservation of environmentally relevant habitats

APR-2021 It is not enough to be renewable, it is necessary to be sustainable. This study showed that Brazil has about 20 million hectares to produce sugarcane or other biomass, intensifying the environmental advantages arising not only from the replacement of fossils, but also the rational use of natural resources, going beyond the mitigation of greenhouse gases. Areas were mapped for expansion considering the preservation of native vegetation, biodiversity and food production.

SCIENCE

Untrafficked furrowed seedbed sustains soil physical quality in sugarcane mechanized fields

MAR-2021 The abundant production of biomass in Brazil suffers from the intense traffic of agricultural machinery that compact and degrade the soil structure, which reduces its productive potential. This work observed, in five years of study, that the use of seedbeds recovers the soil physical and structural quality without the need for mechanical tillage practices. The use of seedbeds system improves root growth and the biological activity of the soil and makes sugarcane production more sustainable, mainly due to the better soil physical quality.

SCIENCE

Developing fibrillated cellulose as a sustainable technological material

FEV-2021 Cellulose from plant biomass can be isolated as fibrils of nanometric diameter, generating building blocks for the development of a new family of renewable technological materials. This work discusses future research directions and highlights key questions for the development of fibrillated cellulose as a platform of novel sustainable biomaterials.

SCIENCE

Two distinct catalytic pathways for GH43 xylanolytic enzymes unveiled by X-ray and QM/MM simulations

JAN-2021 Glycosidases are enzymes involved in lignocellulose breakdown and are central for agro-industrial residues valorization and industrial biotechnology. To enable these enzymes to convert a substrate into the product, several conformational changes occur (catalytic itinerary). This work shows a glycosidase that operates via two distinct catalytic itineraries, breaking the paradigm of the existence of only one possible route for the substrate conversion. The discovery opens new horizons on the molecular functioning of these enzymes and immediately impacts the development of novel biocatalysts.

SCIENCE

Screening of potential endoglucanases, hydrolysis conditions and different sugarcane straws pretreatments for cello-oligosaccharides production

NOV-2020 Molecular biology linked to process development is an important tool for the sustainable use of natural resources such as sugarcane straw. This work has studied the combination of five endoglucanase enzymes for the production of cello-oligosaccharides (COS), potentially useful in the human and animal food sectors. This is the first study that combined the evaluation of different enzymes, conditions, and sugarcane straw pretreatments to optimize COS production in a single step without glucose formation.

SCIENCE

An integrated approach to obtain xylo-oligosaccharides from sugarcane straw: From lab to pilot scale

OCT-2020 The use of crop residues to obtain products with high added value is an important aspect of sustainable development. This work brings new perspectives to value sugarcane straw to bioproducts other than for the production of heat and bioelectricity. It shows the potential of sugarcane straw to produce xylo-oligosaccharides (XOS), a prebiotic substance, and the use of xylanase enzymes to hydrolyze XOS. The study covered the laboratory and pilot-scale (LNBR Pilot Plant) of production.

SCIENCE

Impact of the Melle-Boinot process on the enhancement of second-generation ethanol production by Spathaspora passalidarum

AUG-2020 Microbial biodiversity is a source of solutions in biotechnology. The non-conventional yeast Spathaspora passalidarum is a potential platform for industrial applications aiming to produce cellulosic ethanol and biochemicals due to its natural ability to ferment xylose. This study reports for the first time the use of the Melle-Boinot fermentation process using this yeast, achieving high ethanol yields, demonstrating to be a worthy strategy in the production of biofuels.

SCIENCE

A rationally identified marine GH1 Beta-glucosidase has distinguishing functional features for simultaneous saccharification and fermentation

AUG-2020 New solutions to produce biofuels from sugarcane residues can come from unexpected environments, such as the marine. This work demonstrated the potential use of a marine enzyme β-glucosidase (GH1), rationally identified, in the production of cellulosic ethanol with simultaneous saccharification and fermentation. With activity in celo-oligosaccharides and efficiency in milder temperatures, this enzyme can be used in industrial biotechnological processes that involve the deconstruction of lignocellulosic material.

SCIENCE

Novel xylose transporter Cs4130 expands the sugar uptake repertoire in recombinant Saccharomyces cerevisiae strains at high xylose concentrations

AUG-2020 A major challenge on 2G technologies establishment is the inefficient assimilation of the five-carbon sugar xylose by engineered S. cerevisiae strains, increasing fermentation time. This work describes a novel and efficient xylose transporter, improving xylose uptake especially in high concentrations. The work also investigates the dynamic behavior of the transporter, pointing out residues related to xylose translocation.

SCIENCE

Enzymes knuckle down to the job

JUN-2020 Discovery of new enzymes for health, nutrition, biofuels, and other industrial biotechnological applications. Inspired by the molecular biodiversity of microorganisms this work has deepened the knowledge about new enzymatic strategies for the polysaccharides β-1,3-glucans processing, discovering a new mechanism of polysaccharide recognition and new mode of enzymatic action.

TECHNOLOGY

SUCRE Final Report

JUN-2020 Decarbonization of the electricity sector can benefit from straw, an underutilized sugarcane residue. This report provides an integrated and in-depth analysis of straw-based electricity in Brazil, considering technical, economic, environmental, and societal impacts. Corroborating its relevance to other sugarcane producing countries, SUCRE was a highlight in the report “South-South and Triangular Cooperation on the Bioeconomy“ presented at COP-25.

SCIENCE

Technoeconomic and life-cycle analysis of single-step catalytic conversion of wet ethanol into fungible fuel blendstocks

JUN-2020 Sustainable biofuels are important for decarbonization of hard-to-abate sectors such as aviation, shipping and heavy-duty road transportation. The low cost of ethanol and large production capacity make it attractive to be converted into a hydrocarbon fuel, which is typically done in three steps. This work goes further and describes an economic and environmental analysis of a renewable aviation fuel obtained from a single-step catalytic process using ethanol from biomass as raw material, reducing the need for external hydrogen.

SCIENCE

Substrate and Product-Assisted Catalysis: Molecular Aspects behind Structural Switches along Organic Hydroperoxide Resistance Protein Catalytic Cycle

MAY-2020 Quantum and classical simulations of structurally resolved proteins can further the understanding of biocatalysis in biological systems susceptible to damage by oxidants. This work provides insights on the oxidation response of bacteria cells by investigating the role of the active site and the catalytic pathways to decompose oxidants in Ohr proteins. This is relevant to the identification of inhibitors with therapeutic potential.

SCIENCE

Crystal structure of a novel xylose isomerase from Streptomyces sp. F-1 revealed the presence of unique features that differ from conventional classes

MAY-2020 Biofuels from sugarcane residues require yeasts to metabolize pentoses from xylose and to operate at mild conditions. This is a challenge to enzymatic conversion of xylose to xylulose that can be addressed by reversible changes of enzyme configurations. This work reports two new and unique xylose isomerases with amino-acid substitutions in the catalytic interface and preference for isomerization at milder conditions. Molecular understanding of enzymes can contribute to customization of fermentation processes.

TECHNOLOGY

Process simulation of renewable electricity from sugarcane straw: Techno-economic assessment of retrofit scenarios in Brazil

MAY-2020 Brazil can further reduce greenhouse gas emissions by significantly increasing renewable electricity generated from biomass. This is due to environmental legislation that has progressively prohibited burning before sugarcane harvesting and led to high availability of straw. This work integrates both agricultural and industrial models to provide techno-economic assessments that can enable retrofit investments in existing biorefineries. It highlights the strong dependence on electricity prices of straw recovery projects.

SCIENCE

Rational engineering of the Trichoderma reesei RUT-C30 strain into an industrially relevant platform for cellulase production

MAY-2020 Sustainable biofuels are important for decarbonization of light-vehicle road transportation. Synthetic biology was used to develop a microbial platform for cellulase production to reduce the cost of cellulosic ethanol production. This work describes a Brazilian technology validated at industrial operating conditions, which employs rational design of a public domain strain for cellulosic on-site manufacture of enzymes for ethanol production from sugarcane residues.

SCIENCE

Techno-economic assessment of bioenergy and biofuel production in integrated sugarcane biorefinery: Identification of technological bottlenecks and economic feasibility of dilute acid pretreatment

MAY-2020 The production of cellulosic ethanol still faces challenges to become commercially competitive and impact circular economy. This work evaluated the production of cellulosic ethanol from the dilute acid pretreatment and subsequent enzymatic hydrolysis of the bagasse of a sugarcane hybrid (with low lignin content, high fiber content and high agricultural productivity). It is noteworthy that the costs of sugarcane production, investment in industrial equipment and costs of chemical inputs are the main factors that impact the economic viability of the evaluated process.

SCIENCE

Structural insights into β-1,3-glucan cleavage by a glycoside hydrolase family

MAY-2020 Discovery of new enzymes for health, nutrition, biofuels, and other industrial biotechnological applications. Inspired by the molecular biodiversity of microorganisms this work has deepened the knowledge about new enzymatic strategies for the polysaccharides β-1,3-glucans processing, discovering a new mechanism of polysaccharide recognition and new mode of enzymatic action.

TECHNOLOGY

Engineering aspects of hydrothermal pretreatment: From batch to continuous operation, scale-up and pilot reactor under biorefinery concept

MAR-2020 Sustainable biofuels are important for decarbonization of light-vehicle road transportation. Hydrothermal pre-treatment is considered one of the most promising technologies for cellulosic ethanol production. This review provides comprehensive information on hydrothermal pretreatment, including performance at semi-industrial scale (LNBR pilot plant) and discusses integrated process design.

TECHNOLOGY

Improvement of homologous GH10 xylanase production by deletion of genes with predicted function in the Aspergillus nidulans secretion pathway

MAR-2020 Filamentous fungi are important microbial platforms for biotechnological applications. One challenge is to achieve high protein production titers. In this work, the large-scale transcriptional analysis was used to identify genes involved in protein secretion pathways. Genetic modifications of these target genes resulted in strains with improved protein production, demonstrating it is an interesting strategy for the development of industrially relevant strains.

PARTNERSHIP

Spatially remote motifs cooperatively affect substrate preference of a ruminal GH26-type endo-β-1,4-mannanase

MAR-2020 Enzymes can improve digestibility of mannan oligosaccharides present in cattle diets. Thus, cattle rumen contains a microbial community highly adapted to breakdown of lignocellulosic biomass. This work, with a partnering company, indicates a novel, complex and cooperative mechanism between enzyme subsites and ancillary domain to modulate substrate preference. It furthers the molecular understanding of substrate binding and recognition in the GH26 family and exhibits potential industrial use.

TECHNOLOGY

Functional genomic analysis of bacterial lignin degraders: diversity in mechanisms of lignin oxidation and metabolism

FEB-2020 The valorization of biomass whole constituents is important for the development of new bioproducts and for decarbonization of the economy. In this work, genomic analyzes were used to identify several mechanisms employed by bacteria for the metabolism of lignin. These bacterial pathways may inspire the development of biotechnological applications to convert lignin into value-added products.

TECHNOLOGY

Comparison of Biofuel Life Cycle Analysis Tools

DEC-2019 Life cycle assessment (LCA) is a tool to assess the environmental impacts of a product. LCA model differences challenge credibility of individual evaluations applied to greenhouse gas mitigation targets. This work, in partnership with the International Energy Agency, compares greenhouse gas emissions for cellulosic ethanol production using internationally accepted LCA models from Brazil, Canada, USA and the EU. It provides recommendations to promote transparency and harmonization of LCA models.