Limits...
Improved biomass and protein production in solid-state cultures of an Aspergillus sojae strain harboring the Vitreoscilla hemoglobin.

Mora-Lugo R, Madrigal M, Yelemane V, Fernandez-Lahore M - Appl. Microbiol. Biotechnol. (2015)

Bottom Line: In solid-state cultures, the content of protease, exo-polygalacturonase (exo-PG), and exo-polymethylgalacturonase (exo-PMG) of the transformed fungus (A. sojae vgb+) improved were 26, 60, and 44 % higher, respectively, in comparison to its parental strain (A. sojae wt).No significant difference was observed in endo-polygalacturonase (endo-PG) content between both fungal strains, suggesting dissimilar effects of VHb towards different enzymatic productions.Overall, our results show that biomass, protease, and exo-pectinase content of A. sojae in SSF can be improved by transformation with VHb.

View Article: PubMed Central - PubMed

Affiliation: Downstream Bioprocessing Lab, Jacobs University Bremen gGmbH, Bremen, Germany. r.moralugo@jacobs-university.de.

ABSTRACT
The biotechnological value of Aspergillus sojae ATCC 20235 (A. sojae) for production of pectinases in solid-state fermentation (SSF) has been demonstrated recently. However, a common drawback of fungal solid-state cultures is the poor diffusion of oxygen into the fungi that limits its growth and biological productivity. The bacterial Vitreoscilla hemoglobin (VHb) has favored the metabolism and productivities of various bacterial and yeast strains besides alleviating hypoxic conditions of its native host, but the use of VHb in filamentous fungi still remains poor explored. Based on the known effects of VHb, this study assessed its applicability to improve A. sojae performance in SSF. The VHb gene (vgb) under control of the constitutive Aspergillus nidulants gpdA promoter was introduced into the genome of A. sojae by Agrobacterium-mediated transformation. Successful fungal transformants were identified by fluorescence microscopy and polymerase chain reaction (PCR) analyses. In solid-state cultures, the content of protease, exo-polygalacturonase (exo-PG), and exo-polymethylgalacturonase (exo-PMG) of the transformed fungus (A. sojae vgb+) improved were 26, 60, and 44 % higher, respectively, in comparison to its parental strain (A. sojae wt). Similarly, biomass content was also 1.3 times higher in the transformant strain. No significant difference was observed in endo-polygalacturonase (endo-PG) content between both fungal strains, suggesting dissimilar effects of VHb towards different enzymatic productions. Overall, our results show that biomass, protease, and exo-pectinase content of A. sojae in SSF can be improved by transformation with VHb.

No MeSH data available.


Related in: MedlinePlus

Typical growth of A. sojae wt and A. sojae vgb + on solid substrate during the 10-day fermentation period (only selected days are shown). The column on the left shows a representative flask of the inoculation day (0), and the column on the right shows the non-inoculated control media after 10 days of incubation under the same conditions (C)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4628083&req=5

Fig3: Typical growth of A. sojae wt and A. sojae vgb + on solid substrate during the 10-day fermentation period (only selected days are shown). The column on the left shows a representative flask of the inoculation day (0), and the column on the right shows the non-inoculated control media after 10 days of incubation under the same conditions (C)

Mentions: The growth of the transformant A. sojae vgb + and parental A. sojae wt strain in the solid-state cultures was visually examined. Both fungal strains showed a similar grow pattern during each of the entire fermentation period of 10 days (Fig. 3). The first mold growth was observable 2 days after inoculation, and mycelia were patchily distributed on the substrate. Abundant mycelial growth was observed after 4 days of fermentation with total colonization of the solid substrate by day 6. The first conidia production was observed after 6 to 7 days of fermentation reaching its maximum content by the end of the fermentation at day 10, where conidia are indicated by the green color (Fig. 3).Fig. 3


Improved biomass and protein production in solid-state cultures of an Aspergillus sojae strain harboring the Vitreoscilla hemoglobin.

Mora-Lugo R, Madrigal M, Yelemane V, Fernandez-Lahore M - Appl. Microbiol. Biotechnol. (2015)

Typical growth of A. sojae wt and A. sojae vgb + on solid substrate during the 10-day fermentation period (only selected days are shown). The column on the left shows a representative flask of the inoculation day (0), and the column on the right shows the non-inoculated control media after 10 days of incubation under the same conditions (C)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4628083&req=5

Fig3: Typical growth of A. sojae wt and A. sojae vgb + on solid substrate during the 10-day fermentation period (only selected days are shown). The column on the left shows a representative flask of the inoculation day (0), and the column on the right shows the non-inoculated control media after 10 days of incubation under the same conditions (C)
Mentions: The growth of the transformant A. sojae vgb + and parental A. sojae wt strain in the solid-state cultures was visually examined. Both fungal strains showed a similar grow pattern during each of the entire fermentation period of 10 days (Fig. 3). The first mold growth was observable 2 days after inoculation, and mycelia were patchily distributed on the substrate. Abundant mycelial growth was observed after 4 days of fermentation with total colonization of the solid substrate by day 6. The first conidia production was observed after 6 to 7 days of fermentation reaching its maximum content by the end of the fermentation at day 10, where conidia are indicated by the green color (Fig. 3).Fig. 3

Bottom Line: In solid-state cultures, the content of protease, exo-polygalacturonase (exo-PG), and exo-polymethylgalacturonase (exo-PMG) of the transformed fungus (A. sojae vgb+) improved were 26, 60, and 44 % higher, respectively, in comparison to its parental strain (A. sojae wt).No significant difference was observed in endo-polygalacturonase (endo-PG) content between both fungal strains, suggesting dissimilar effects of VHb towards different enzymatic productions.Overall, our results show that biomass, protease, and exo-pectinase content of A. sojae in SSF can be improved by transformation with VHb.

View Article: PubMed Central - PubMed

Affiliation: Downstream Bioprocessing Lab, Jacobs University Bremen gGmbH, Bremen, Germany. r.moralugo@jacobs-university.de.

ABSTRACT
The biotechnological value of Aspergillus sojae ATCC 20235 (A. sojae) for production of pectinases in solid-state fermentation (SSF) has been demonstrated recently. However, a common drawback of fungal solid-state cultures is the poor diffusion of oxygen into the fungi that limits its growth and biological productivity. The bacterial Vitreoscilla hemoglobin (VHb) has favored the metabolism and productivities of various bacterial and yeast strains besides alleviating hypoxic conditions of its native host, but the use of VHb in filamentous fungi still remains poor explored. Based on the known effects of VHb, this study assessed its applicability to improve A. sojae performance in SSF. The VHb gene (vgb) under control of the constitutive Aspergillus nidulants gpdA promoter was introduced into the genome of A. sojae by Agrobacterium-mediated transformation. Successful fungal transformants were identified by fluorescence microscopy and polymerase chain reaction (PCR) analyses. In solid-state cultures, the content of protease, exo-polygalacturonase (exo-PG), and exo-polymethylgalacturonase (exo-PMG) of the transformed fungus (A. sojae vgb+) improved were 26, 60, and 44 % higher, respectively, in comparison to its parental strain (A. sojae wt). Similarly, biomass content was also 1.3 times higher in the transformant strain. No significant difference was observed in endo-polygalacturonase (endo-PG) content between both fungal strains, suggesting dissimilar effects of VHb towards different enzymatic productions. Overall, our results show that biomass, protease, and exo-pectinase content of A. sojae in SSF can be improved by transformation with VHb.

No MeSH data available.


Related in: MedlinePlus