The effect of lyophilization and storage time on the survival rate and hydrolytic activity of Trichoderma strains

Abstract

The study evaluates the survivability and storage stability of seven Trichoderma strains belonging to the species: T. harzianum (1), T. atroviride (4), and T. virens (2) after the lyophilization of their solid state cultures on wheat straw. Biomass of Trichoderma strains was freeze-dried with and without the addition of maltodextrin. Furthermore, in order to determine the ability of tested Trichoderma strains to preserve selected technological features, the biosynthesis of extracellular hydrolases (cellulases, xylanases, and polygalacturonases) after a 3-month storage of lyophilizates was investigated. Strains of T. atroviride (except TRS40) and T. harzianum TRS85 showed the highest viability after lyophilization process (up to 100%). After 3 months of storage, T. atroviride TRS14 exhibited the highest stability (95.23%); however, the number of active conidia remained at high level of 106–107 cfu/g for all tested T. atroviride strains and T. harzianum TRS85. Interestingly, after a 3-month storage of lyophilized formulations, most of the tested Trichoderma strains exhibited higher cellulolytic and xylanolytic activities compared to the control, i.e., before freeze-drying process. The highest activities of these enzymes exhibited the following: T. atroviride TRS14–2.37 U/g and T. atroviride TRS25–21.47 U/g, respectively, whereas pectinolytic activity was weak for all tested strains, with the highest value of 0.64 U/g registered for T. virens TRS109.

The effects of compound treatment of Aspergillus oryzae and fibrolytic enzyme on in vitro degradation, gas production and fermentative profile of maize silage and sugarcane silage

“…The culture medium (sugarcane bagasse and wheat bran) overgrown with fungi A. oryzae was preserved by lyophilization. Freeze-drying was performed with a lyophilizer (Semi-Industrial Freeze Dryer LJI010) at an external manifold with a pressure of 0.2 mbar for 20 h (Grzegorczyk et al ., 2018). The CFU counting was 6 × 10 8 /g of dried A. oryzae .…”

Enzymatic and Antimicrobial Activity of Biologically Active Samples from Aloe arborescens and Aloe barbadensis

“…Slightly higher activity was present in A. arborescens samples. It should be emphasized that the difference in enzyme activities may appear due to the type of sample (fresh, lyophilized, extract), as the enzyme activity can be maintained or even increased by the lyophilization process [ 55 ].…”

Estabilidad de cepas nativas de Trichoderma conservadas mediante liofilización

“…Para los tratamientos almacenados a 28°C se alcanzaron medias por encima del 80% en la mayoría de los casos (Tabla 3). Esto podría estar relacionado con los excipientes empleados para la liofilización, ya que la Malta se considera una sustancia protectora de secado que tiene un efecto osmorregulador sobre el microorganismo (Teixido et al, 2005;Grzegorczyk et al, 2018).…”

“…Los cultivos se agitaron diariamente a mano para mantener las condiciones aeróbicas de Trichoderma spp. y favorecer la conservación de la biomasa en el proceso de liofilización (Grzegorczyk et al, 2018).…”

“…Malta como agente protector. Estos resultados difieren a los obtenidos porGrzegorczyk et al (2018), quienes registran cepas con concentraciones superiores a 8 7×10 UFC/g sobre paja de arroz como sustrato de fermentación después del período de incubación de tres meses utilizando malto dextrina como agente protector Tewari y Bhanu (2004),. alcanzaron produc-8 ciones de conidios de 2,8 ×10 UFC/g utilizando paja Rev.…”