Abstract (1) Background: Oxygen supply is an important parameter to be considered in submerged cultures. This study evaluated the influence of different conditions for dissolved oxygen (DO) concentration on laccases activities and growth of Pleurotus sajor-caju PS-2001 in submerged process in stirred-tank bioreactor. (2) Methods: Initially, three different conditions were tested: uncontrolled DO and minimum levels of 30% and 80% of saturation, with the pH controlled between 4.5 and 7.0. (3) Results: Best results were observed at 30% DO (26 U mL-1 of laccases at 96 h), whereas higher mycelial biomass was observed at 30% and 80% DO (above 4.5 g L-1). Four different conditions of DO (uncontrolled, 10%, 30% and 50% of saturation) were tested at pH 6.5, with higher laccases activity (80 U mL-1 at 66 h) and lower mycelial growth (1.36 g L-1 at 90 h) being achieved with DO of 30%. In this test, the highest values for volumetric productivity and specific yield factor were determined. Under the different pH conditions tested, the production of laccases is favoured at DO concentration of 30% of saturation, while superior DO levels favours fungal growth. (4) Conclusion: The results indicate that dissolved oxygen concentration is a critical factor for the culture of P. sajor-caju PS-2001 and has important effects not only on laccases production but also on fungal growth.

Resumo: Thyropteridae é uma família de morcegos endêmica da região Neotropical e Thyroptera devivoi é a única espécie da família que ocorre exclusivamente em manchas florestais das savanas do norte de América do Sul e do Cerrado Brasileiro. Dados primários da espécie são ainda escassos e o objetivo deste estudo foi preencher lacunas de conhecimento sobre distribuição geográfica, uso de abrigos e padrões de ecolocalização da espécie. Nós observamos uma colônia de T. devivoi com 15 indivíduos vivendo sob uma folha morta de palmeira. Os morcegos usaram a folha como abrigo ao menos por quatro dias. Depois de capturar um indivíduo, nós confirmamos a identificação da espécie por meio da morfologia do crânio e do disco adesivo. O novo registro reforça a associação da espécie com formações não florestais e a ocorrência principalmente em savanas. Os chamados de ecolocalização de T. devivoi são consistentes com o conhecido para o gênero, com pulsos multi-harmônicos de baixa intensidade e alta frequência. A despeito destes novos dados, mais estudos são certamente necessários para aprimorar os dados de distribuição assim como os requerimentos biológicos da espécie.

Abstract: Thyropteridae is a family of bats endemic to the Neotropical region, and Thyroptera devivoi is the only species in the family that occurs exclusively in forest patches within savannas of northern South America and north of the Brazilian Cerrado. Primary data on the species are still scarce. Therefore, in this study our objective was to fill knowledge gaps on geographical distribution, roost-use, and echolocation for the species. We observed a T. devivoi colony of 15 individuals living under a dead palm leaf. The bats used the leaf as a roost for at least four days. After capturing one individual, we confirmed the species identification via skull size and the oblong shape of the adhesive disk. The new record reinforces the association of this species with non-forested formations, and its occurrence mainly in savannas. Echolocation calls of T. devivoi are consistent with those known for the genus, with multiharmonic, low intensity and high frequency pulses. Despite these new data, more studies are certainly needed to enhance distribution data for the species, as well as to clarify the biological and ecological requirements of the species.

(1) Background: In this study, the effects of different pH values (2.4, 3.2, 4.4 and 5.0), temperatures (30, 35, 40, 45 and 50°C) and agitation (100 rpm) on the enzymatic decolourisation of twenty-two dyes belonging to the chromophore groups anthraquinone, azo and triphenylmethane were assessed. (2) Methods: In all conditions, it was used a crude enzyme broth containing 30 U mL-1 laccases produced by Pleurotus sajor-caju PS-2001 in submerged process. (3) Results: Regarding the effects of pH values, the best results were obtained at pH 3.2 and 30°C, in which bleaching was observed for all dyes evaluated. In assays conducted at different temperatures, highest levels of decolourisation were observed at 35°C and pH 3.2 for nineteen of the dyes assessed. Thirteen dyes presented colour reduction exceeding 50% after the enzymatic treatment, including all acid and all disperse dyes evaluated. The reciprocal agitation of 100 rpm promoted negative effect on decolourisation. (4) Conclusion: From the results achieved, one can conclude that the laccase-containing preparation of P. sajor-caju PS-2001 has potential for the decolourisation of some dyes widely used in different industrial sectors, especially in the textile industry, and therefore could be used in future strategies for the biotreatment of coloured wastes.

RESUMO: O objetivo deste trabalho foi estimar parâmetros de adaptabilidade e estabilidade para touros da raça Nelore em três regiões diferentes. As características analisadas foram o peso aos 420 dias de idade (P420) e a idade ao primeiro parto (IPP) de animais criados em regime de pasto. As informações utilizadas no estudo foram referentes a média fenotípica das fêmeas, filhas dos dez melhores touros classificados com base em uma região. Para avaliar os parâmetros de adaptabilidade e a estabilidade foram utilizadas as metodologias propostas por FINLAY & WILKINSON (1963) e EBERHART & RUSSELL (1966). As médias estimadas pelos métodos dos quadrados mínimos foram de 243,91±34,90kg e 1182,54±157,82 dias, respectivamente, para as características P420 e IPP. Os parâmetros de adaptabilidade e estabilidade para a característica P420 mostraram que é possível identificar os touros com comportamento previsível nos diferentes ambientes e que poderão gerar progênies com desempenho acima da média. O comportamento dos dez touros analisados nas diferentes regiões estudadas para as características P420 e IPP, evidenciaram que os rebanhos e as regiões influenciaram na performance de suas progênies. Por meio das metodologias aplicadas é possível identificar touros com adaptabilidade geral, alta estabilidade e com melhores desempenhos, os quais seriam os mais adequados a se utilizar em rebanhos em que não se conhece o mérito genético das vacas e nem o ambiente onde serão criadas as progênies.

ABSTRACT: The present study aimed to estimate adaptability and stability parameters for Nellore bulls in 3 different regions. The traits analyzed included the weight of the animals raised in pasture at 420 days of age (W420) and at the age at first calving (AFC). The information used in this study was related to the phenotypic mean of the females which were the offspring of the top ten classified bulls based in one region. We used the methods proposed by Finlay & Wilkinson (1963) & Eberhart and Russell (1966) in order to evaluate the parameters of adaptability and stability of these animals. The averages estimated by the method of least squares were 243.91±34.90 kg and 1182.54±57.82 days, respectively, for the traits W420 and AFC. Adaptability and stability parameters for the W420 characteristic showed that it is feasible to identify bulls with predictable behavior in different environments, and that these animals may generate progenies which may achieve above-average performance. Behavior of the 10 bulls analyzed in the different regions studied for the traits W420 and AFC showed that the herds and the regions influenced the performance of their progenies. The methods used allowed us to identify bulls with general adaptability, high stability, and better performances, which may be the most suitable to be used in herds in which the genetic merit of the cows and the environment where the progenies will be raised are both unknown.

RESUMO A dermatite atópica é uma doença de pele comum. O aumento da incidência mudou o foco da pesquisa em dermatite atópica para epidemiología, prevenção e tratamento. Evidências sugerem que a microbiota intestinal desempenha um papel importante na patogênese da dermatite atópica, induzindo imunossupressão, mas o mecanismo exato ainda não está claro. Os probióticos foram amplamente divulgados para atuar no sistema imunológico. Eles são microrganismos vivos com efeitos imunomoduladores que estimulam as citocinas Th1 e suprimem a resposta Th2 que vem sendo pesquisada para o tratamento de diversas doenças. Probióticos mais comumente usados são parte da microflora intestinal como lactobacilos, bifidobactérias e enterococos. Descrevemos um caso de resposta evidente ao uso de probióticos em uma menina com dermatite atópica grave, com grande alteração nos escores de gravidade da dermatite atópica (BSA/Scorad/FDLQI). A modulação da microbiota intestinal com probióticos pode oferecer uma maneira de prevenir ou tratar doenças alérgicas, incluindo a dermatite atópica.

SUMMARY Atopic dermatitis is a common skin disease. Its increased incidence has changed the focus of research on atopic dermatitis toward epidemiology, prevention, and treatment. Evidence suggests that intestinal microbiota plays an important role in the pathogenesis of atopic dermatitis inducing immunosuppression, but its exact mechanism is still unclear. Probiotics have been widely reported to act on the immune system. They are living microorganisms with immunomodulatory effects that stimulate Th1 cytokines and suppress the Th2 response, which are being researched for the treatment of several diseases. Probiotics most commonly used are part of the intestinal microflora like lactobacilli, bifidobacteria, and enterococci. We describe here a case of evident response to the use of probiotics in a girl with severe atopic dermatitis, with a significant change in severity scores of atopic dermatitis (BSA/SCORAD/FDLQI). Modulation of the intestinal microbiota with probiotics may offer a way to prevent or treat allergic diseases, including atopic dermatitis.

Lactobionic acid and its salts are substances that have several applications in the pharmaceutical area. These products were obtained by bioconversion through the enzymatic complex glucose-fructose-oxidoreductase (GFOR)/gluconolactonase (GL) present in calcium alginate immobilized cells of Zymomonas mobilis. In the reactions catalyzed by this enzyme system, the medium pH must be controlled at slightly acid values. For this purpose, NaOH, KOH, or Ca(OH)2 were used, and as a result, the respective salts were formed. The kinetic study on the formation of sodium, potassium and calcium lactobionates was followed by the steps of purification and characterization aiming the potential use of these compounds in the pharmaceutical area. In the assays for the bioproduction of sodium, potassium or calcium lactobionates, yields of 74, 77 and 84% were obtained, respectively. In the salts purification step, purity levels of approximately 95% were achieved. The structural identities of the lactobionate salts were determined by high resolution mass spectrometry, in addition to the 13C and 1H NMR analysis. The characterization demonstrates the selectivity of the enzymatic reaction of GFOR/GL of Z. mobilis, in the production of lactobionic acid and its salts.

Resumo Atualizamos a lista de mamíferos do estado de Mato Grosso do Sul, Brasil com base em registros primários. Cento e sessenta e seis espécies são listadas como ocorrentes no estado, sendo 47 de mamíferos de médio e grande porte, 46 de pequenos mamíferos e 73 de morcegos. As espécies listadas estão distribuídas em 31 famílias: Didelphidae (17 spp.), Dasypodidae (7 spp.), Myrmecophagidae (2 spp.), Cebidae (1 sp.), Callithrichidae (2 spp.), Aotidae (1 sp.), Pitheciidae (1 sp.), Atelidae (1 sp.), Leporidae (1 sp.), Felidae (7 spp.), Canidae (4 spp.), Mustelidae (5 spp.), Mephitidae (2 sp.), Procyonidae (2 spp.), Tapiridae (1 sp.), Tayassuidae (2 spp.), Cervidae (4 spp.), Sciuridae (1 sp.), Cricetidae (22 spp.), Erethizontidae (1 sp.), Caviidae (3 spp.), Dasyproctidae (1 sp.), Cuniculidae (1 sp.), Echimyidae (4 spp.), Phyllostomidae (41 spp.), Emballonuridae (2 spp.), Molossidae (16 spp.), Vespertilionidae (9 spp.), Mormoopidae (1 sp.), Noctilionidae (2 spp) e Natalidade (1 sp.). Estes números representam um aumento de quatorze espécies com registro primário para o estado em comparação com a listagem publicada anteriormente. Ainda assim, é evidente a escassez de informações em diversas regiões do estado, e a necessidade de implementação de coleções zoológicas regionais. O estado de Mato Grosso do Sul representa apenas 4,19% do território brasileiro, mas o número de mamíferos atinge 24,13% do total de espécies que ocorrem no país.

Abstract We updated the checklist of mammals from Mato Grosso do Sul, Brazil based on primary records only. One hundred and sixty-six mammal species were listed as occurring in the state, 47 of them being medium to large, 47 small mammal and 73 bat species. The listed species are distributed in 31 families: Didelphidae (17 spp.), Dasypodidae (7 spp.), Myrmecophagidae (2 spp.), Cebidae (1 sp.), Callithrichidae (2 spp.), Aotidae (1 sp.), Pitheciidae (1 sp.), Atelidae (1 sp.), Leporidae (1 sp.), Felidae (7 spp.), Canidae (4 spp.), Mustelidae (5 spp.), Mephitidae (2 spp.), Procyonidae (2 spp.), Tapiridae (1 sp.), Tayassuidae (2 spp.), Cervidae (4 spp.), Sciuridae (1 sp.), Cricetidae (22 spp.), Erethizontidae (1 sp.), Caviidae (3 spp.), Dasyproctidae (1 sp.), Cuniculidae (1 sp.), Echimyidae (4 spp.), Phyllostomidae (41 spp.), Emballonuridae (2 spp.), Molossidae (16 spp.), Vespertilionidae (9 spp.), Mormoopidae (1 sp.), Noctilionidae (2 spp.), and Natalidade (1 sp.). These numbers represent an increase of fourteen species with primary records for the state in comparison with the previously published checklist. However, it is evident the scarcity of information at several regions of the state, and the need of implementation of regional zoological collections. The state of Mato Grosso do Sul represent only 4.19% of the Brazilian territory, but the number of mammal species reach 24.13% of the known species occurring in the country.

RESUMO. Utilizaram-se informações de 3.871 bezerros puros e cruzados, provindos de fêmeas das raças: Nelore, Brangus, Wagyu e 1/2 Brangus vs. 1/2 Nelore, as quais receberam o sêmen proveniente de touros das raças Aberdeen Angus, Red Angus, Brangus, Nelore e Wagyu para avaliar efeitos sobre o peso a desmama, ganho diário de peso do nascimento a desmama e o número de dias para se obter 160 kg de bezerros nascidos na sub-região do Pantanal de Aquidauana (Brasil), avaliando correlações fenotípicas entre as características. Analisaram-se os dados, utilizaram-se dois modelos estatísticos. O primeiro incluiu efeitos de raça do touro, grupo genético da vaca, sexo, ano de nascimento (AN), estação de nascimento (EN) e interação AN*EN. O segundo incluiu grupo genético do bezerro, sexo, AN, EN e interação AN*EN. Grupo genético da vaca e interação AN*EN do bezerro não influenciou (p < 0.05) no peso ao desmame. Observou-se peso médio ao desmame para filhos de touros Aberdeen Angus de 177,7 ± 3,3 kg, Red Angus de 180,3 ± 3,5 kg, Brangus de 181,48 ± 3,2 kg, Nelore de 175,4 ± 3,6 kg e Wagyu de 173,1 ± 3,0 kg.

ABSTRACT. Purebred and crossbred calves (n = 3,871) were selected that were born in the sub-region of the Pantanal of Aquidauana (Brazil), derived from Nellore, Brangus, Wagyu, and 1/2 Brangus + 1/2 Nellore cows, which were artificially inseminated by bulls of the Aberdeen Angus, Red Angus, Brangus, Nellore, and Wagyubreeds. Parameters such as weaning weight, daily gain from birth to weaning, and the number of days to gain 160 kg, were assessed inthese calves and phenotypic correlations between the traits were evaluated. Data were analyzed using two statistical models. The first model included sire breed effects, the genetic group of the cow, sex, year of birth (AN), birth season (EN), and the interaction AN * EN. The second model included the genetic group of the calf, sex, AN, EN, and the interaction AN * EN. The genetic group of the cow and calf and the interaction AN * EN did not significantly affect body weight (p < 0.05). The average weaning weights of progeny were as follows: Aberdeen Angus bulls, 177.70 ± 3.28 kg; Red Angus, 180.31 ± 3.46 kg; Brangus, 181.48 ± 3.15 kg; Nellore, 175.43 ± 3.60 kg; and Wagyu, 173.16 ± 2.96 kg.

In this work, a protocol for the formulation of an enzyme concentrated product to be applied in fruit juice treatment is described. Downstream processing conditions for the recovery and concentration of pectinases produced by the new strain Aspergillus niger LB-02-SF in solid state cultivation were assessed. The solid-liquid ratio in the extraction step of pectinases recovery from the cultivated media was evaluated and the highest activity was obtained with a solid-liquid ratio of 1:10. The crude extract was concentrated by ultrafiltration and the total pectinase (TP) activity was 73.6-fold concentrated in relation to the crude extract, and a final TP titer of 663 U mL–1 was obtained with 73.7% of recovery yield. KCl and different glycerol concentrations were added to the concentrated extract and the stability of pectinases during the storage at 5°C for 59 weeks was tested. The formulation with 50% w/w glycerol was applied to the treatment of apple and grape juices and the results of these tests were statistically comparable to those obtained with two high-quality commercial preparations.

In the present study, the effect of pectinases on the production of pulp and juice of araçá and the presence of bioactive compounds were evaluated. An enzyme extract (EE) produced by Aspergillus niger LB-02-SF in solid state fermentation and the commercial enzyme Ultrazym®AFP-L were used in this study. After enzyme treatment with the EE preparation, the extraction yield increased by 23.1% and viscosity decreased by 42.8%, during pulp maceration. During juice processing, there was an increase of 70.6% in clarification and a decrease of 72.87% in turbidity. Higher values of these parameters, 47.7, 69.0, 80.7, and 79.7%, respectively, were obtained using the Ultrazym®AFP-L, which also led to a significant increase in the polyphenol content, both in the pulp (24%) and in the juice (28%), with a less pronounced effect when the EE was applied (10 and 21%, respectively). The anthocyanins content in the araçá pulp increased after treatment with the commercial preparation (23%), and there was no significant increase with the use of EE. The use of Ultrazym®AFP-L increased the β-carotene content by 29.4% in the fruit pulp, while the treatment with EE did not result in significant changes compared with those of the juice and pulp controls.

Endo-polygalacturonase (endo-PG) production by Aspergillus niger T0005/007-2 in solid medium with 170 mm of height was evaluated in a cylindrical double surface bioreactor in 96-h experiments. Cell concentration close to 92 mg.g -¹ dm (mg per g of dry medium) in the standard condition (static) was achieved, whereas in tests under forced aeration of 1.4 and 2.8 L.min-1. Kg-1 mm (L of air per minute per Kg of moist medium) and with the central shaft fungal biomass attained approximately 100 mg.g-1 dm. Superior endo-PG activity was obtained with the central-shaft system, 78 U.g-1 dm (units per g of dry medium). Forced aeration and pressure pulse showed no positive effect on the production of endo-PG, 45 U.g-1 dm and 28 U.g-1 dm, respectively. None of the conditions evaluated was efficient for medium temperature control. Endo-PG was stable up to 40ºC. The activity decreased in 50% after 120 minutes at 50ºC, which is a temperature normally found during this process.

Um meio líquido contendo farelo de trigo, sais e fonte de indutor (pectina) foi definido para a produção de exo e endo-poligalacturonases por Aspergillus oryzae CCT3940. A indução por pectina purificada foi significativamente maior que a observada com cascas de cítricos. O crescimento de A. oryzae é favorecido por valores de pH próximos a 4, embora uma queda até valor em torno de 3 seja necessária para a produção das enzimas. Posteriormente, atividades decrescentes foram observadas com a subida normal do pH até próximo à neutralidade. As maiores atividades foram alcançadas quando o processo foi iniciado em pH 4 e controlado quando decresceu até níveis ligeiramente abaixo de 3 (159 unidades.mL-1 para endo-PG, em 83 h, e 45 unidades.mL-1, em 64 h, para exo-PG), com a perda de atividades sendo drasticamente reduzida. Os melhores valores de pH e temperatura para a ação de exo-PG (4,5/57°C) e endo-PG (4,3/40ºC) foram estimados.

A liquid medium containing wheat bran, salts and a source of inducer (pectin) was found to be suitable for the production of exo- and endo-polygalacturonases by Aspergillus oryzae CCT3940. Induction of polygalacturonases by purified pectin was significantly higher than when rinds of citrus fruits were used as inducer. A. oryzae growth was favoured by pH close to 4, although a drop of pH to around 3 was needed for enzymes production. Afterwards, decreasing activities were observed with the normal increase in pH to near neutrality. The highest activities were achieved with an initial pH of 4 and controlled when it decreased to a value slightly below 3 (159 units endo-PG.mL-1 at 83 h and 45 units exo-PG.mL-1 at 64 h), being the loss in polygalacturonases activities strongly reduced at this condition. The best values of pH and temperature for the action of exo-PG (4.5/57ºC) and endo-PG (4.3/40ºC) were assessed.

Sorbitol e ácido glucônico são produzidos por células previamente cultivadas da bactéria produtora de etanol Zymomonas mobilis pela ação das enzimas periplasmáticas glicose-frutose oxidorredutase (GFOR) e glucono-delta-lactonase (GL). A atividade de GFOR/GL em células a serem empregadas nesta bioconversão depende das condições de crescimento. Em cultivo em regime descontínuo, com concentrações iniciais de glicose (S0) entre 42 e 230 g/L, as maiores atividades específica e total de GFOR/GL foram obtidas com S0 = 153 g/L (12,6 U/g de células e 62 U/L), enquanto maiores S0 levaram a atividades decrescentes em células não tratadas. Com S0 = 209 g/L, a atividade específica final foi de 7 U/g, mas, após a ruptura das células, atividade superior a 15 U/g foi medida. Uma vez que em descontínuo observou-se inibição por substrato com S0 a partir de 153 g/L, ensaios em regime descontínuo alimentado, com glicose equivalente a 230 g/L em descontínuo, foram realizados. Embora a inibição pelo substrato tenha sido superada, a atividade permaneceu baixa (5,2 U/g). Um novo ensaio em descontínuo alimentado, conduzido sob baixa pressão para remover o etanol do meio, resultou em atividade específica de 9,8 U/g e total de 68,7 U/L. Estes resultados indicam que as baixas atividades em células de Z. mobilis cultivadas com maiores S0 se deveram a mudanças na parede celular, provocadas por concentrações elevadas de etanol, que dificultaram o transporte de substrato para as enzimas intracelulares durante a bioconversão. Esta conclusão foi confirmada em ensaios de bioconversão com células provenientes de cultivos em diferentes condições.

Previously grown cells of the ethanologenic bacterium Zymomonas mobilis produce sorbitol and gluconic acid, in reactions catalysed by the periplasmic enzymes glucose-fructose oxidoreductase (GFOR) and glucono-delta-lactonase (GL). The GFOR/GL system activity, in cells to be used in this bioconversion, depends on growth conditions. In batch runs, with initial glucose concentrations (S0) from 42 to 230 g/L, the highest specific and total GFOR/GL activities were obtained with S0 = 153 g/L (12.6 U/g cells and 62 U/L). Higher S0 led to decreasing activities in fresh cells. With S0 = 209 g/L, the final specific activity was only 7.0 U/g. After disruption of cells, however, an activity over 15 U/g was revealed. Since growth inhibition with S0 over 153 g/L was observed in batch mode, fed-batch runs, equivalent to a batch of 230 g/L, were done. Although no growth inhibition occurred in fed-batch cultivation, enzyme activity remained low (5.2 U/g). A further fed-batch experiment, carried out under low pressure to remove ethanol from the medium, resulted in a specific activity of 9.8 U/g and a total activity of 68.7 U/L. These results indicate that the low GFOR/GL activities in Z. mobilis cells grown on higher S0 were due to changes in the cell wall, caused by high concentration of ethanol, that hindered the transport of the substrate to the intracellular enzymes in biconversion runs. This conclusion was confirmed by bioconversion runs with cells cultivated under different conditions.

Em regime descontínuo, o crescimento celular e a formação de 2,3-butanodiol/acetoína por Klebsiella pneumoniae sofrem inibição por concentrações iniciais de sacarose (S0) acima de 60 g/L. Sob condições não inibidoras, uma velocidade máxima de consumo de sacarose de 1,5 g/L/h foi observada. Entretanto, com S0 = 204 g/L, esta velocidade decresceu para 0,15 g/L/h. A fermentação de 204 g/L de sacarose por K. pneumoniae levou à formação de 84,3 g/L de mistura 2,3-butanodiol/acetoína, com uma conversão de 0,41 g/g e uma produtividade de 1,06 g/L/h. Um maior suprimento de oxigênio aumentou a velocidade global do processo mas reduziu a conversão em produto. Em regime descontínuo alimentado, a inibição foi evitada, tendo sido atingida uma concentração final de produtos de 80,0 g/L, com uma produtividade de 2,63 g/L/h e uma conversão de 0,37 g/g.

In batch mode, Klebsiella pneumoniae growth and 2,3-butanediol/acetoin formation are increasingly inhibited by initial sucrose concentrations (S0) over 60 g/L. At non inhibitory conditions, a maximum sucrose consumption rate of 1,5 g/L/h was measured. With S0=204 g/L however, this rate decreased to 0.15 g/L/h. K. pneumoniae fermented 204 g/L sucrose to produce 84.3 g/L of a mixture 2,3-butanediol/acetoin with a yield of 0.41 g/g and a productivity of 1.06 g/L/h. Higher oxygen transfer rates improved the overall process rate but the product yield was reduced. Avoiding substrate inhibition, by performing the fermentation in fed-batch mode, a final 2,3-butanediol/acetoin concentration of 80.0 g/L was achieved. In this case, a productivity of 2.63 g/L/h and a product yield of 0.37 g/g were calculated.