Mixed culture fermentation between Rhizopus nigricans and Trichoderma pseudokoningii to control cucumber Fusarium wilt

The bioproduction of caproate from organic waste by anaerobic mixed culture is a very attractive technology for upgrading low-grade biomass to a high-value resource. However, the caproate production process is markedly restricted by the feedback inhibition of caproate. In this study, four types of anion-exchange resin were investigated for their enhancing capability in caproate fermentation of anaerobic mixed culture. The strong base anion-exchange resin D201 showed the highest adsorption capacity (62 mg/g), selectivity (7.50), and desorption efficiency (88.2%) for caproate among the test resins. Subsequently, the optimal desorption temperature and NaOH concentration of eluent for D201 were determined. The adsorption and desorption efficiency of D201 remained stable during eight rounds of the adsorption–desorption cycle, indicating a satisfactory reusability of D201. Finally, performances of caproate fermentation with and without resin adsorption for carboxylate were evaluated. The results demonstrated that the final concentration of caproate was improved from 12.43 ± 0.29 g/L (without adsorption) to 17.30 ± 0.13 g/L (with adsorption) and the maximum caproate production rate was improved from 0.60 ± 0.01 g/L/d to 2.03 ± 0.02 g/L/d. In the group with adsorption, the cumulative caproate production was increased to 29.10 ± 0.33 g/L broth, which was 134% higher than that of the control group. Therefore, this study provides effective approaches to enhance caproate production.

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Mixed-culture fermentation for enhanced C21-hydroxylation of glucocorticoids

Journal of Biotechnology ◽

10.1016/j.jbiotec.2020.03.008 ◽

2020 ◽

Vol 314-315 ◽

pp. 14-24

Author(s):

Lisa König ◽

Sabine Szczesny ◽

Simone Brixius-Anderko ◽

Rita Bernhardt ◽

Frank Hannemann

Keyword(s):

Mixed Culture ◽

Mixed Culture Fermentation

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Rotations with Indian Mustard and Wild Rocket Suppressed Cucumber Fusarium Wilt Disease and Changed Rhizosphere Bacterial Communities

Microorganisms ◽

10.3390/microorganisms7020057 ◽

2019 ◽

Vol 7 (2) ◽

pp. 57 ◽

Cited By ~ 6

Author(s):

Xue Jin ◽

Jian Wang ◽

Dalong Li ◽

Fengzhi Wu ◽

Xingang Zhou

Keyword(s):

Bacterial Community ◽

Fusarium Wilt ◽

Bacterial Community Composition ◽

Indian Mustard ◽

Wilt Disease ◽

Crop Rotations ◽

Pseudomonas Spp ◽

Fusarium Wilt Disease ◽

Wild Rocket ◽

Cucumber Fusarium Wilt

Crop monocropping usually results in an enrichment of soil-borne pathogens in soil. Crop rotation is an environmentally friendly method for controlling soil-borne diseases. Plant rhizosphere microorganisms, especially plant-beneficial microorganisms, play a major role in protecting plants from pathogens, but responses of these microorganisms to crop rotation remain unclear. Here, we evaluated the effects of rotations with Indian mustard (Brassica juncea) and wild rocket (Diplotaxis tenuifolia (L.) DC.) on cucumber Fusarium wilt disease caused by Fusarium oxysporum f.sp. cucumerinum Owen (FOC). Cucumber rhizosphere bacterial community composition was analyzed by high-throughput amplicon sequencing. Bacteria, Pseudomonas spp., 2,4-diacetylphloroglucinol (an antifungal secondary metabolite) producer and FOC abundances were estimated by real-time PCR. Rotations with Indian mustard and wild rocket suppressed cucumber Fusarium wilt disease and cucumber rhizosphere FOC abundance. Crop rotations increased cucumber rhizosphere bacteria, Pseudomonas spp. and 2,4-diacetylphloroglucinol producer abundances. Moreover, crop rotations changed cucumber rhizosphere bacterial community composition and increased bacterial community diversity. However, crop rotations decreased soil inorganic nitrogen content and inhibited cucumber seedling growth. Overall, rotations with Indian mustard and wild rocket suppressed cucumber Fusarium wilt disease, which might be linked to the increased rhizosphere bacterial diversity and abundances of potential plant-beneficial microorganisms (such as Pseudomonas spp. and 2,4-diacetylphloroglucinol producer).

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