Monoseptic growth of fungal lipase producers under minimized sterile conditions: Cultivation of Phialemonium curvatum in 350 L scale

Abstract

A disadvantage of most microbial production processes is the need for sterile techniques. The objective of this study was the development of a robust fungal system allowing monoseptic growth with a minimum of sterile technique in plastic barrels. Selective growth conditions were achieved by mineral salts medium, known for the cultivation of Botrytis cinerea, but containing rapeseed oil instead of glucose as the sole source of carbon and energy. Furthermore, pH 3 was adjusted. A screening of fungi suitable for that system revealed Phialemonium curvatum AW02 isolated from compost. P. curvatum AW02 was superior in comparison with four further fungal isolates because high titers of hydrophilic spores were found in submerged production. Second, a biofilm formation on plastic segments or moving beds made harvesting of the biomass comfortable. Cultivations with volumes of 100 or 350 L showed no contaminations by bacteria when all conditions were controlled. Two independent approaches showed the dependance of growth on lipases in the cultivation system. A B. cinerea strain knocked out in lip1 showed reduced growth in comparison to the wild type because the first catabolic step is the triglyceride hydrolysis. P. curvatum AW02 lipase activity was detected. More than 90% was found to be cell wall associated. Solid shear stress liberated two active proteins showing IEPs of 4.7 or 5.6.

Approaching Immobilization of Enzymes onto Open Porous Basotect®

“…Specific activity assays, as described in the literature [39,41], were utilized. For lipase activity measurements, the hydrolysis of the fatty acid derivative p-nitrophenyl palmitate was used, and laccase activity was detected by transformation of ABTS.…”

“…A few working groups [38] applied melamine-based resins in pyrolysis to form templates for mostly non-enzymatic catalysts. Furthermore, BT was used as the moving bed for fungal lipase producers [39]. Using BT as a carrier material for catalytically-active enzymes, either adsorptively or covalently bound, is a completely new approach.…”

Initial phases of microbial biofilm formation on opaque, innovative anti‐adhesive surfaces using a modular microfluidic system

“…They can cause numerous problems [11][12][13], hence it is important to understand biofilm formation and development processes on surfaces in order to develop resistant materials and avoidance strategies. But they are used for biotechnological applications as well [6,14,15].…”

Editorial: Bioprocess‐oriented plant design – turning basic research into practical applications

“…A couple of highlights out of the broad spectrum of inspiring talks are presented in this special issue. It includes contributions from numerous hot spots of German and Swiss bioprocess engineering groups in Aachen (Jochen Büchs) 1, Braunschweig (Ezequiel Franco‐Lara) 2, Hamburg (Reiner Luttmann) 3, Kaiserlautern (Ulber) 4, Munich (Dirk Weuster‐Botz and Thomas Becker) 5–7, Senftenberg (Klaus‐Peter Stahmann) 8, Wädenswil/Zurich (Dieter and Regine Eibl) 9 and Dresden with myself 10, 11. Additionally a technical report of one of the leading companies in the field of bioreactor development and production, Satorius Stedim, is included 11.…”

“…However, because these fungi are not well understood and they are so heterogeneous, bioengineering for these processes is still needed. Two contributions in this issue show novel bioreactor design and developments in this field 8, 11. Further articles deal with monitoring and control strategies for economic and safe operation of new plants in biotechnology 6, 7.…”