Modern morphological engineering techniques for improving productivity of filamentous fungi in submerged cultures

Abstract

Morphological engineering techniques have recently gained popularity as they are used for increasing the productivity of a variety of metabolites and enzymes in fungi growing in submerged cultures. Their action is mainly associated with the changes they evoke in fungal morphology. Traditional morphological engineering approaches include manipulation of spore concentration, pH-shifting and mechanical stress exerted by stirring and aeration. As the traditional methods proved to be insufficient, modern techniques such as changes of medium osmolality or addition of mineral microparticles to the media (microparticle-enhanced cultivation, MPEC) were proposed. Despite the fact that this area of knowledge is still being developed, there are a fair amount of scientific articles concerning the cultivations of filamentous fungi with the use of these techniques. It was described that in Ascomycetes fungi both MPEC or change of osmolality successfully led to the change of mycelial morphology, which appeared to be favorable for increased productivity of secondary metabolites and enzymes. There are also limited but very promising reports involving the successful application of MPEC with Basidiomycetes species. Despite the fact that the mineral microparticles behave differently for various microorganisms, being strain and particle specific, the low cost of its application is a great benefit. This paper reviews the application of the modern morphology engineering techniques. The authors critically assess the advantages, shortcomings, and future prospects of their application in the cultivation of fungi.

Salt‐enhanced cultivation as a morphology engineering tool for filamentous actinomycetes: Increased production of labyrinthopeptin A1 in Actinomadura namibiensis

“…The development of methods for tailor-made morphologies of filamentous microorganisms is summarized under the term morphology engineering [18,22,[30][31][32]62]. Together with empirical modeling of different strain types, this method is used as a tool to increase product concentrations.…”

Morphological evolution of various fungal species in the presence and absence of aluminum oxide microparticles: Comparative and quantitative insights into microparticle‐enhanced cultivation (MPEC)

“…Although the aforementioned studies involved the use of the MPEC for loosening the mycelia and elevating enzyme levels, Gonciarz and Bizukojć () demonstrated the use of talc for decreasing pellet diameter and increasing product titers in the lovastatin‐oriented cultivation of Aspergillus terreus ATCC 20542. Other examples of MPEC‐related studies were reviewed by Antecka, Bizukojć, and Ledakowicz (), Krull et al. (), and Walisko et al.…”

Effects of Cotton Seed Powder as the Seed Medium Nitrogen Source on the Morphology and Pneumocandin B0 Yield of Glarea lozoyensis

“…Morphological engineering, defined as “tailoring morphologies for specific bioprocesses” ( Mcintyre et al, 2001 ), encompasses all actions aimed at controlling fungal morphology ( Antecka et al, 2016 ). Morphological engineering techniques include varying the spore concentration, pH-shifting, mechanical stress exerted by stirring and aeration, and regulating medium osmolarity ( Nielsen et al, 1995 ; Papagianni, 2004 ; Cheng et al, 2009 ; Wucherpfennig et al, 2011 ).…”