Lignocellulosic Bioethanol Research Articles

Optimization of consolidated bioprocessing by response surface methodology in the conversion of corn stover to bioethanol by thermophilic Geobacillus thermoglucosidasius.

The swift depletion of fossil fuels and their associated environment and economic impact has led the world to explore the sustainable alternate fuels. Amidst the available alternatives lignocellulosic bioethanol provides the edge over the exhausting fossil fuels. In this current study, Response surface methodology, a mathematical and statistical tool was used to optimize the fermentation conditions in consolidated bioprocessing of corn stover by Geobacillus thermoglucosidasius. The impact of inoculum concentration, temperature, pH, agitation speed and time in bioethanol fermentation were screened with Plackett-Burman design and it was farther optimized with central composite design. The analysis by PBD confirmed the significant impact of fermentation time, inoculum concentration, and temperature of the fermentation process. Further, it was optimized with CCD. This showed that 15% v/v of Inoculum concentration, 50°C of temperature and fermentation time of 72h increased the bioethanol concentration to a maximum of 9.04g/L with 0.45g/g significant yield and a conversion efficiency of 88%. Thus, the CCD showed a satisfactory result in consolidated bioprocessing of bioethanol from corn stover. Thus, in the future, this approach of optimization will yield a good base for consistent production of bioethanol.

The role of nonfood bioethanol production in neutralizing China's transport carbon emissions: An integrated life cycle environmental-economic assessment

Lignocellulosic bioethanol may contribute significantly to neutralizing global greenhouse gases emissions as an alternative fuel, but controversies have increasingly arisen in relevant researches as to whether the ethanol production pathway is environmental- and cost-competitive or not and which hotspots may impede its commercial-scale deployment. Here we explore a cost-effective biorefinery pathway of sugarcane bagasse, molasses and Dioscorea composite hemls, from an integrated environmental and economic assessment model to evaluate the performance of bioethanol, as an alternative to gasoline, characterized by gCO2eq and MSP, in terms of its emission mitigation potential and cost, as well as its other environmental impacts with the CML method of assessment. Specifically, this study examines the production of 1 ton bioethanol with the considered environmental and economic indicators by three defensible allocation approaches affecting the total mitigation potential with anywhere between 20% and 82.5%, where the electricity consumed in the process of the bioethanol conversion is produced with more sustainable means, increasing the emission savings by up to 48.5%. The economic competitivity have also been examined to promote dialogues across environmental and economic fields, exemplified by the emission mitigation cost with the calculation of minimum selling price at 49.1/ton CO2eq, comparable with the EU-ETS carbon permit price. Signs of advantages abound in the current emission trading scheme, where the decrease in carbon tax levels can cut down the price of bioethanol production, especially with regard to the supply chain collaboration with electricity, and thus enhance the overall revenue of neutralizing transport emissions.

Bioengineering and Molecular Biology of Miscanthus

Miscanthus is a perennial wild plant that is vital for the production of paper and roofing, as well as horticulture and the development of new high-yielding crops in temperate climates. Chromosome-level assembly of the ancient tetraploid genome of miscanthus chromosomes is reported to provide resources that can link its chromosomes to related diploid sorghum and complex polyploid sugarcane. Analysis of Miscanthus sinensis and Miscanthus sacchariflorus showed intense mixing and interspecific hybridization and documented the origin of a high-yielding triploid bioenergetic plant, Miscanthus × giganteus. The Miscanthus genome expands comparative genomics functions to better understand the main abilities of Andropogoneae herbs. Miscanthus × giganteus is widely regarded as a promising lignocellulosic biomass crop due to its high-biomass yield, which does not emit toxic compounds into the environment, and ability to grow in depleted lands. The high production cost of lignocellulosic bioethanol limits its commercialization. The main components that inhibit the enzymatic reactions of fermentation and saccharification are lignin in the cell wall and its by-products released during the pre-treatment stage. One approach to overcoming this barrier could be to genetically modify the genes involved in lignin biosynthesis, manipulating the lignin content and composition of miscanthus.

Effects of harvest time on bioethanol production and bagasse characteristics for combustion and forage in sweet sorghum

Determining the optimal harvest time is very crucial to achieve sustainable production of first-generation bioethanol as well as efficient use of its bagasse for combustion or feed in sweet sorghum. The aim of the current research was to understand the effects of different harvest times, which comprised flowering (FLW), soft dough (SD), hard dough (HD), and physiological maturity (PM) on the bioethanol production and the combustion and forage characteristics of its bagasse in sweet sorghum. In one study, averaged over a period of 2 years, the mean theoretical total ethanol yield (TEY) was between 4802 and 5316 L ha–1. The PM harvest produced the highest TEY, which was followed by the HD and SD harvests, with sligh differences. These results suggested that sweet sorghum should be harvested at any phenological stage after FLW to achieve sustainable total (juice + lignocellulosic) bioethanol production in a semi-arid Mediterranean environment. Averaged over a period of 2 years, the mean dry bagasse yield (DBY) achieved from the harvest times herein ranged between 12.0 and 14.1 t ha–1. As with TEY, the PM harvest exhibited the highest DBY and desirable bagasse combustion caharacteristics due to exhibiting the lowest moisture and ash contents, which indicated that it seemed be the most suitable harvest time if obtaining solid biofuel production from the bagasse is the main target after the production of juice ethanol. On the other hand, the HD harvest provided the highest bagasse forage quality among the harvest times due to exhibiting the significantly lowest neutral detergent fiber and acid detergent fiber contents, but the significantly highest relative feed value. These results suggested that the HD harvest time was the most suitable for sweet sorghum cultivation when producing juice ethanol that is complemented by the production of forage utilizing the bagasse.

Transcriptomes analysis of Pichia kudriavzevii UniMAP 3–1 in response to acetic acid supplementation in glucose and xylose medium at elevated fermentation temperature

The yeast Pichia kudriavzevii is gaining attention as a potential lignocellulosic bioethanol producer due to its multiple stress tolerance characteristics. RNA sequencing was performed to analyze the transcriptomics profiling of an isolated strain, Pichia kudriavzevii UniMAP 3–1 in response to acetic acid supplementation at 40ºC in individual glucose and xylose medium. Acetic acid was found to be consumed simultaneously with glucose when grown in glucose media. Transcriptomics profiling revealed that the response of P. kudriavzevii UniMAP 3–1 towards acetic acid includes activation of differentially expressed genes (DEGs) involved in tricarboxylic acid (TCA) cycle, ATP-binding cassette (ABC) transporters, and folding, sorting and degradation, both in glucose and xylose media. Conversely, DEGs involved in energy metabolism were only apparent in xylose media. DEGs categorized under glycolysis, lipid metabolism, amino acid metabolism and hexose transporters are mainly repressed in response to acetic acid supplementation. These results provide new insights on P. kudriavzevii response to acetic acid supplementation in glucose and xylose media during high temperature fermentation, and serve as an important basis to uncover the regulatory mechanisms involved. This study will also provide reference for future studies in developing engineered strains possessing high tolerance to inhibitors at high temperature bioethanol production.

Current Trends in Lignocellulosic Bioethanol Production

In view of crude oil prices, and its environmental issues, utilization of sustainable renewable alternative energies such as biofuels is rapidly progressing in many countries. The increasing global energy demand and depleting fossils fuels sources has led to search alternative clean and renewable fuels. One of the best alternatives to the gasoline is lignocellulosic bioethanol. Recent researches on lignocellulosic bioethanol focuses on advancement of pretreatment techniques for improved sugar yields and decreased inhibitors production. Pretreatment technique with no or less use of chemicals and cost effectiveness is the main purpose of most of the researches. Biological pretreatment techniques produce less fermentation inhibitors than chemical pretreatments. In order to cope with fermentation inhibitors different strategies can be adopted during pretreatment processes. In the course of time, advancements in production process over separate hydrolysis and fermentation have been introduced. Simultaneous saccharification and co/fermentation; and consolidated bioprocessing for bioethanol production are gaining popularity among researchers. Int. J. Appl. Sci. Biotechnol. Vol 10(1): 1-11.

Quantification of Microbial Robustness in Yeast.

Stable cell performance in a fluctuating environment is essential for sustainable bioproduction and synthetic cell functionality; however, microbial robustness is rarely quantified. Here, we describe a high-throughput strategy for quantifying robustness of multiple cellular functions and strains in a perturbation space. We evaluated quantification theory on experimental data and concluded that the mean-normalized Fano factor allowed accurate, reliable, and standardized quantification. Our methodology applied to perturbations related to lignocellulosic bioethanol production showed that the industrial bioethanol producing strain Saccharomyces cerevisiae Ethanol Red exhibited both higher and more robust growth rates than the laboratory strain CEN.PK and industrial strain PE-2, while a more robust product yield traded off for lower mean levels. The methodology validated that robustness is function-specific and characterized by positive and negative function-specific trade-offs. Systematic quantification of robustness to end-use perturbations will be important to analyze and construct robust strains with more predictable functions.

Underutilized Lignocellulosic Waste as Sources of Feedstock for Biofuel Production in Developing Countries

The need for a reliable and sustainable energy source, stability in energy price and solution to environmental challenges of fossil fuel has led to searching for an alternative energy source to fossil fuel. Several alternative sources have been developed over time, but they are limited in one form or another. However, biofuel such as bioethanol has been identified as a superb alternative with superior properties to fossil fuel. One major challenge with biofuel is the high production cost resulting from feedstock, which may also serve as a food source. In order to address this challenge, research is focused on searching for cheap and sustainable feedstock for biofuel production. Currently, attention is on lignocellulosic waste as feedstock with a keen interest in developing the most appropriate technique for processing it to bioethanol, especially in developing countries, which is the focus of this review. This review involves converting lignocellulosic waste to bioethanol and the pretreatment steps involved as well as its challenges, prospect and economic aspect. Among the pretreatment steps reported, biological treatment remains outstanding but with a few challenges which can be managed. Biofuel has come to stay in developing countries with lots of opportunities that favours its production cost. Although the high cost of enzyme production has been identified as a challenge to the economic viability of lignocellulosic bioethanol, there is hope that developing an efficient bio-system for simultaneous saccharification and fermentation (SSF) and consolidated biomass processing may help circumvent the challenge. In conclusion, the effective utilization of lignocellulosic waste in an efficient biocatalyst system can serve as an economically viable means to overcome the challenge posed by fossil fuel.

Partial energy integration between biofuels production processes: Effect on costs, CO2 emissions and process safety

Energy integration is a tool which allows reducing the heating and cooling requirements for production processes. This is particularly important in the processes for production of biofuels, since such processes are expected to have low environmental impact, which can be achieved by reducing the need for steam and cooling water. It is common to perform energy integration by making use of all the available streams. This approach may allow reducing as much as possible utilities’ requirements, but other indicators may be affected, such as capital costs, since the number of required equipment is increased. Thus, in this work the effect of performing partial integration is assessed, i.e., selecting only a few streams to perform the energy integration. The effect of increasing the number of integrated streams is assessed in terms of sustainability indicators based on the green chemistry principles. The studied indicators are utilities’ requirements, total annual cost, environmental impact (assessed through CO2 emissions) and safety (assessed through the HPSI index). The study is applied to the energy integration of a supercritical biodiesel production process and a lignocellulosic bioethanol production process.

Bioethanol from Napier grass employing different fermentation strategies to evaluate a suitable operation for batch bioethanol production

• Variations in substrate and enzyme additions in SSF of Napier grass were compared. • SHF and SSF resulted in 30.6 g/L and 28.5 g/L ethanol from 15% Napier grass. • Alleviate mixing problem by portioning addition did not improve ethanol production. • Pre-incubating the grass before SSF negatively impacts ethanol production. • Extra loading of substrate during SSF resulted in higher ethanol production. Napier grass has been used as animal feed especially in countries with tropical climates. As interest in alternative feedstocks for fuel bioethanol increases, Napier grass has been considered as a potential feedstock for lignocellulosic bioethanol production. Two main fermentation strategies, including separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF), were investigated with various substrate and enzyme feeding patterns in SSF. Total substrate loading of 15% and enzyme dosage of 40 FPU/g substrate were controlled to compare the performance of each fermentation variation. SHF and SSF resulted in similar ethanol production of 30.6 ± 0.4 g/L and 28.5 ± 2.3 g/L. Preincubation of grass and enzyme resulted in significant lower ethanol at 20.3 ± 1.6 g/L. Portioning the addition of grass and enzyme did not change the ethanol production significantly. Increasing the grass loading to 30% via portioning approach resulted in an increase in ethanol production in batch fermentation, while the addition of extra enzyme did not help with increasing ethanol production.

Selection of Superior Yeast Strains for the Fermentation of Lignocellulosic Steam-Exploded Residues.

The production of lignocellulosic ethanol calls for a robust fermentative yeast able to tolerate a wide range of toxic molecules that occur in the pre-treated lignocellulose. The concentration of inhibitors varies according to the composition of the lignocellulosic material and the harshness of the pre-treatment used. It follows that the versatility of the yeast should be considered when selecting a robust strain. This work aimed at the validation of seven natural Saccharomyces cerevisiae strains, previously selected for their industrial fitness, for their application in the production of lignocellulosic bioethanol. Their inhibitor resistance and fermentative performances were compared to those of the benchmark industrial yeast S. cerevisiae Ethanol Red, currently utilized in the second-generation ethanol plants. The yeast strains were characterized for their tolerance using a synthetic inhibitor mixture formulated with increasing concentrations of weak acids and furans, as well as steam-exploded lignocellulosic pre-hydrolysates, generally containing the same inhibitors. The eight non-diluted liquors have been adopted to assess yeast ability to withstand bioethanol industrial conditions. The most tolerant S. cerevisiae Fm17 strain, together with the reference Ethanol Red, was evaluated for fermentative performances in two pre-hydrolysates obtained from cardoon and common reed, chosen for their large inhibitor concentrations. S. cerevisiae Fm17 outperformed the industrial strain Ethanol Red, producing up to 18 and 39 g/L ethanol from cardoon and common reed, respectively, with ethanol yields always higher than those of the benchmark strain. This natural strain exhibits great potential to be used as superior yeast in the lignocellulosic ethanol plants.

Towards a better understanding of the HTL process of lignin-rich feedstock

The hydrothermal liquefaction reactions (HTL) in subcritical conditions of a lignin residue has been studied on a lab scale. The starting material was a lignin rich residue co-produced by an industrial plant situated in Northern Italy producing lignocellulosic bioethanol. The reactions were carried out in batch mode using stainless steel autoclaves. The experiments were under the following operating conditions: two different temperatures (300–350 °C), the presence of basis catalysts (NaOH, and NH4OH) in different concentrations and the presence/absence of capping agent 2,6-bis-(1,1-dimethylethyl)-4-methylphenol (BHT). Lignin residue and reaction products were characterized by analytical and spectroscopic techniques such as CHN-S, TGA, GC–MS, EPR, and 1H-NMR with (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (T.E.M.P.O.). The addition of BHT did not significantly affect the yield of char which is formed by radical way. Spectroscopic analysis indicated that the level of radicals during the reaction was negligible. Therefore, the results obtained experimentally suggest that the reaction takes place via an ionic route while radical species would play a minor role.

Can crop residues provide fuel for future transport? Limited global residue bioethanol potentials and large associated land, water and carbon footprints

Bioethanol production from non-crop based lignocellulosic material has reached the commercial scale and is advocated as a possible solution to decarbonize the transport sector. This study evaluates how much presently used transport related fossil fuels can be replaced with lignocellulosic bioethanol using crop residues, calculates greenhouse gas emission savings, and determines lignocellulosic bioethanol's land, water, and carbon footprints. We estimate global bioethanol production potential from 123 crop residues in 192 countries and 20 territories under different environmental constraints (optimistic and realistic sustainable potentials) versus no constraints (theoretical potential) on residue availability. Previous studies on global bioethanol production potential from lignocellulosic material focused on one or few biomass feedstocks, and excluded (un)constrained residue availability scenarios. Our results suggest the global net lignocellulosic bioethanol output ranges from 7.1 to 34.0 EJ per annum replacing between 7% and 31% of oil products for transport yielding relative emission savings of 338 megatonne (Mt; 70%) to 1836 Mt (79%). Emission savings range from 4% to 23% of total transport emissions in the realistic sustainable versus theoretical potential. Land, water and carbon footprints of net bioethanol vary between potentials, countries/territories, and feedstocks, but overall exceed footprints of conventional bioethanol. Averaged footprints range between 0.14 and 0.24 m2 land per megajoule (MJ−1), 74–120 L water MJ−1, and 28–44 g CO2 equivalent MJ−1, with smaller footprints in the theoretical potential caused by the exclusion of secondary residues and low price of alternative biomass chains in the sustainable potential.

Growth of thermotolerant Pichia kudriavzevii UniMAP 3-1 strain for ethanol production using xylose and glucose at different fermentation temperatures

The applications of thermotolerant microorganisms in the production of lignocellulosic bioethanol is the key factor for successful simultaneous saccharification and fermentation process. Thus, this study aimed to isolate a thermotolerant yeast strain that was able to convert both glucose and xylose into ethanol. An analysis based on D1/D2 region of the large-subunit ribosomal DNA identified the isolated strain namely as Pichia kudriavzevii UniMAP 3-1. The growth of this newly isolated yeast was tested with fermentation temperature at 30°C and 40°C on xylose and glucose. P. kudriavzevii UniMAP 3-1 was able to ferment xylose to ethanol at both 30°C and 40°C with a yield of 0.013 g/g and 0.019 g/g with concomitant xylitol yield of 0.24 g/g and 0.25 g/g, respectively. Fermentation of glucose to ethanol was also tested at 30°C and 40°C and the yields were 0.42 g/g and 0.41 g/g, respectively. The potential of this thermotolerant yeast to be used in high-temperature fermentation in both glucose and xylose are proven in this study.

Optimal fed-batch bioreactor operating strategies for the microbial production of lignocellulosic bioethanol and exploration of their economic implications: A step forward towards sustainability and commercialization

The enduring adoption of greener technologies from the biofuel manufacturing industries requires the balanced integration of multiple inter-disciplinary concerns (i.e., engineering, business, sustainability, societal) to make production processes more attractive to the industrial sector. From an engineering perspective, the commercial establishment of lignocellulosic bioethanol plants is still hindered by increased production cost. High product concentrations with improved yield and productivity at the fermentation stage seem to be inviolable condition to straightly compete with fossil-based and first-generation bioethanol facilities. This study proposes a model-based multi-objective dynamic optimization approach to systematically derive optimal operating policies for the fermentation bioreactor as a step forward towards enhancing the economic performance of lignocellulosic bioethanol plants. The economic benefit of the derived optimal bioreactor strategies is evaluated via a scalable economic index, linking for the first time the performance of the fermentation bioreactor to the economics of the entire production process. It is demonstrated that high values in productivity and substantial compromises in yield and final bioethanol concentration are conditions which favor economic feasibility with the achieved fermentation performance (3.32 g L−1 h−1, 0.399 g g−1, 106.0 g L−1) being comparable to first-generation bioethanol production. Finally, a global system analysis framework is employed to investigate the robustness of the optimal value of the economic index to the variability of key model parameters, illustrating the impact of model uncertainty on the process economic performance.

Investigation of Water Hyacinth as a Feedstock for Bioethanol Production by Simultaneous Saccharification and Fermentation Process

As an abundant biomass of surface water, water hyacinth was used as an input material to produce bioethanol in this study. Steam explosion and alkaline pre-treatment were applied on the material before simultaneous saccharification and fermentation (SSF) process was carried out. Experimental data suggested the optimal enzyme dosage be 1.0 wt% of the dry mass of the biomass, and the mass of the material be up to 8.0 wt% of the whole mixture in a one-step loading procedure to obtain the climax efficiency after 78 h. The process does not need additional nitrogen nutrition, such as corn steep liquor (CSL), as those in other common lignocellulosic bioethanol processes, because water hyacinth itself contains much protein in its chemical composition. Protein content analysis showed that it was 17.2 wt% (on dry basis), similar to what reported in some published studies. The SSF efficiency was positively 72.8 % at the optimal conditions resulted out from the experiments. Such a convenient conversion of water hyacinth to bioethanol is not only meaningful in term of biofuel production but also in term of environmental treatment.

Multicriteria evaluation of biomass residues in Portugal to second generation bioethanol production

Abstract Paper aims This study evaluates agricultural and forest residues in Portugal to select the best candidates to use in second generation bioethanol (2G bioethanol) production. Originality The growth in the significance and level of decisions in biomass resources to 2G bioethanol and the involved complexity clearly encourage a research strategy to identify and select the wastes according to a multiplicity of criteria. Research method To address the key research objective this research used a multicriteria decision analysis method, MACBETH, to structuring the values of concern and identifying the key criteria, to evaluating the main agricultural and forest waste with respect to each criterion, to weighting the criteria and analyzing the biomass residues overall attractiveness and exploring the model´s results. Main findings As main findings of the study we found that Eucalyptus waste is the most promising forest residue to produce lignocellulosic bioethanol followed by Paulownia Tomentosa waste. The utilization of forest residues to the production of bioethanol in Portugal may represent in the future an important economic activity with huge environmental benefits. Implications for theory and practice The multicriteria approach addressed the research objectives and is simple to use with great potential for circular economy strategy issues. The step-by-step explanation of the model building makes the approach highly acceptable to other practitioners.

Evaluation of designed consortium SNH-1 for efficient hydrolysis of agriculture waste to benefit bioethanol production

Abstract An environment friendly and cost-effective approach is a major bottleneck in biofuels production from agriculture waste residue. The present study unravels the enzymatic hydrolytic potential of a designed bacterial consortium (SNH-1) comprised of camel rumen derived B. safensis CRN 13, B. subtilis CRN 16, C. braakii CRN 21, B. circulans CRN 24, and P. dendritiformis CRN18. The consortium SNH-1 was evaluated for exo-glucanase (0.29 U/ml), β-glucosidase (0.69U/ml), β-glucuronidase (0.29U/ml), endoxylanase (0.79U/ml), arabinosidase (0.62U/ml), α-galactosidase (0.36 U/ml), and endoglucanase (0.51U/ml) activity. Genome analysis of consortium members identified 660 carbohydrate-active enzymes (CAZyme) responsible for breaking the structural intricacy. These include 296 glycoside hydrolase, 19 auxiliary activity, 186 glycosyl transferases, and 37 carbohydrate-binding modules genes. The designed consortium hydrolyzed sugarcane bagasse, wheat straw, and rice straw effectively. Response surface methodology (RSM) was applied to optimize the pH, temperature, and substrate concentration, which has resulted in a 23% higher saccharification of wheat straw. Further, 6.2% bioethanol production was estimated from wheat straw hydrolysate using S. cerevisiae. The wheat straw saccharification by the designed consortium is a cost-effective, chemical-free, cleaner, and promising approach for producing lignocellulosic bioethanol.

Variations in structure and saccharification efficiency of biomass of different sorghum varieties subjected to aqueous ammonia and glycerol pretreatments

Sorghum biomass is a potential feedstock for lignocellulosic bioethanol production. The selection of suitable sorghum variety is essential to obtain high ethanol yield. In this paper we screened sorghum varieties belonging to sweet sorghum, post rainy sorghum, and hybrid sorghum. These varieties were screened based on their agronomic traits, amenability to pretreatment methods, and enzymatic digestibility. The sorghum biomass was pretreated using glycerol (60 %) at 190 ̊C for 60 min and aqueous ammonia (15 %) at 120 ̊C for 60 min. The digestibility of the pretreated biomass was determined using commercial cellulase (Cellic CTec2) at 10U/g loading, and the structural changes in the pretreated biomass were analyzed by spectroscopy and scanning electron microscopy. Sweet sorghum varieties showed significant variations in phenotypic traits such as fresh stalk yield, dry fodder yield, and juice yield. The cellulose digestibility among the sorghum varieties after the pretreatment also differed significantly. The cellulose digestibility levels of glycerol range from 64 % to 89 % and ammonia pretreated sorghum from 63 % to 81 %. The total sugar yields varied from 227 mg/g to 356 mg/g and 209 mg/g to 313 mg/g for sorghum pretreated with ammonia and glycerol, respectively. Although the delignification of sorghum varieties was higher (31%–65%) after ammonia pretreatment than glycerol pretreatment, the cellulose digestibility was higher for the glycerol pretreated biomass. These results indicated that effect of delignification on cellulose digestibility is trivial. This study explores factors affecting pretreatment and cellulose digestibility of sorghum varieties for maximum sugar yield in the cellulosic ethanol process.

Characterisation of Electrochemical Sensor-Array for Utilisation in Construction of BOD Bioelectronic Tongue

Abstract There is need to rapidly measure biochemical oxygen demand (BOD) to estimate organic pollution in wastewater. Biosensors are able to estimate BOD values within 5–30 minutes, but they have some limitations that can be overcome with biosensor-array. This work used sensor-array, which consists of 8 × 3 electrodes. The working electrode was inner Pt circle electrode, counter electrode was a Pt band electrode and the reference electrode was a silver wire. The potentiostat was used to record cyclic voltammetry and chronoamperometry. The pumping speed was set at 1.5 cm3 min−1 or higher, to avoid the interference. Next, sensor-array was tested to measure different oxygen amounts and calibrated accordingly. Lastly, Pseudomonas putida membranes were calibrated and used to estimate BOD value. The calibration gave linear range up to 85 mg L−1 of BOD and sensitivity from 0.0018 to 0.0068. Real industrial wastewater, from lignocellulosic bioethanol production, was used to test the biosensor-array. It underestimated BOD values from 8 to 37 %. This biosensor-array allows to measure BOD value in less than 15 minutes.