Native yeasts for alternative utilization of overripe mango pulp for ethanol production / Levaduras nativas para la utilización alternativa de pulpa de mango senescente para la producción de etanol

Mango fruits (Mangifera indica L.) are highly perishable, causing postharvest losses and producing agroindustrial waste. In the present work, native yeasts were used to evaluate ethanol production in overripe mango pulp. The two isolated strains showed similar sequences in the 18S rDNA region corresponding to Kluyveromyces marxianus, being different to the data reported in the NCBI database. Values of up to 5% ethanol (w/v) were obtained at the end of fermentation, showing a productivity of 4g/l/day, a yield of up to 49% of ethanol and a process efficiency of 80%. These results represent a viable option for using the surplus production and all the fruits that have suffered mechanical injury that are not marketable and are considered as agroindustrial waste, thus achieving greater income and less postharvest losses.

Las frutas de mango (Mangifera indica L.) son altamente perecederas, lo cual causa pérdidas poscosecha y produce desechos agroindustriales. En el presente trabajo, se utilizaron 2 levaduras nativas para evaluar la producción de etanol en pulpa de mango senescente. Las 2 cepas aisladas mostraron similitud en la región 18S ADNr, correspondiente a Kluyveromyces marxianus, la cual es diferente a lo reportado en la base de datos del NCBI. Se obtuvieron valores de hasta el 6% de etanol (v/v) al final de la fermentación, con una productividad de hasta 4g/l/día, un rendimiento de hasta 49% de etanol y una eficiencia en el proceso fermentativo del 80%. Esto representa una opción viable para utilizar excedentes de producción o frutos que han sufrido daño mecánico y no son comercializables, al lograr más ingresos y menos pérdida poscosecha.

Native yeasts for alternative utilization of overripe mango pulp for ethanol production.

Mango fruits (Mangifera indica L.) are highly perishable, causing postharvest losses and producing agroindustrial waste. In the present work, native yeasts were used to evaluate ethanol production in overripe mango pulp. The two isolated strains showed similar sequences in the 18S rDNA region corresponding to Kluyveromyces marxianus, being different to the data reported in the NCBI database. Values of up to 5% ethanol (w/v) were obtained at the end of fermentation, showing a productivity of 4g/l/day, a yield of up to 49% of ethanol and a process efficiency of 80%. These results represent a viable option for using the surplus production and all the fruits that have suffered mechanical injury that are not marketable and are considered as agroindustrial waste, thus achieving greater income and less postharvest losses.

Study of enzymatic saccharification of Agave leaves biomass to yield fermentable sugars.

Agave is a good source of polysaccharides for the production of fermentable sugars as sustainable bioenergy feedstock solutions for semi-arid and arid lands. This plant grows in arid areas, which correspond to a large territory in northern Mexico. Having lignocellulose as the polysaccharide of interest, the information for the enzymatic saccharification of this kind of material is limited. Agave cell walls have a unique recalcitrant nature, but having a high cellulose content, makes this plant material an interesting research subject. In this work, acidic, alkaline and aqueous pretreatments were evaluated to generate a biomass rich in cellulose. The saccharification of pretreated Agave leaves-residue was evaluated under experimental designs to identify the most suitable conditions for enzymatic hydrolysis. Maximum value obtained was 31% glucose, which further increased to 41.4% at extended hydrolysis time of 96 h. The highest cellulose-saccharification reached was up to 61.81%, making Agave atrovirens an alternative for bioethanol production in its geographical area of cultivation.