The Efficacy of Encapsulated Phytase Based on Recombinant Yarrowia lipolytica on Quails' Zootechnic Features and Phosphorus Assimilation.

In this study, we used the Manchurian golden breed of quails. We assessed the efficacy of the food additives of the phytase from Obesumbacterium proteus encapsulated in the recombinant Yarrowia lipolytica yeast, which was supplied at a concentration of 500 phytase activity units per kg of the feed. One hundred fifty one-day-old quails were distributed into six treatment groups. The results showed that adding the O. proteus encapsulated phytase to the quails' diets improved live weight, body weight gain, and feed conversion compared to those in the control groups and the groups using a commercial phytase from Aspergillus ficuum. The results obtained during the experiments indicate a high degree of assimilation of phytate-containing feeds if the encapsulated phytase was fed by the quails compared to that in the other groups. We can conclude that the class D encapsulated phytase is an expedient additive to the diets possessing better kinetic features compared to the PhyA and PhyC classes phytases when it acts inside the quail's chyme.

Advances in immobilization of phytases and their application.

The review describes the advances in the phytase immobilization for the past decade and their biotechnological applications. Different approaches for phytase immobilization are described including the process using organic and inorganic matrices and microbial cells, as well as nanostructures of various nature. Moreover, the immobilization of phytase-producing microbial cells and the use of cross-linked phytase aggregates have been under consideration. A detailed classification of various carriers for immobilization of phytases and the possibility of their applications are presented. A particular attention is drawn to a breakthrough approach of biotechnological significance to the design of microencapsulation of bacterial phytase from Obesumbacterium proteus in the recombinant extremophile of Yarrowia lipolytica.

Neurospora crassa Light Signal Transduction Is Affected by ROS.

In the ascomycete fungus Neurospora crassa blue-violet light controls the expression of genes responsible for differentiation of reproductive structures, synthesis of secondary metabolites, and the circadian oscillator activity. A major photoreceptor in Neurospora cells is WCC, a heterodimeric complex formed by the PAS-domain-containing polypeptides WC-1 and WC-2, the products of genes white collar-1 and white collar-2. The photosignal transduction is started by photochemical activity of an excited FAD molecule noncovalently bound by the LOV domain (a specialized variant of the PAS domain). The presence of zinc fingers (the GATA-recognizing sequences) in both WC-1 and WC-2 proteins suggests that they might function as transcription factors. However, a critical analysis of the phototransduction mechanism considers the existence of residual light responses upon absence of WCC or its homologs in fungi. The data presented point at endogenous ROS generated by a photon stimulus as an alternative input to pass on light signals to downstream targets.