to accomplish the worldwide demand for recombinant human erythropoietin (rhuepo) as a therapeutic, application of cost-efficient expression system of methylotrophic yeast pichia pastoris (p. pastoris) rather than mammalian cells is indispensable. herein, a report on high levels secreted-expression of pichia-derived rhuepo by batch fermentation in a ph stabilized format is presented. the full le...

In this study, we have compared YOLOv4, a single-shot detector to Faster-RCNN, two-shot detect and classify whiteflies on yellow-sticky tape (YST). An IoT remote whitefly monitoring station was developed placed in rearing room. Images of attracted the trap were recorded 2× per day. A total 120 images labeled using labeling software split into training testing dataset, 18 additional yellow-stick...

We present optical trapping and surgery of living yeast cells using two operational modes of a single laser. We used a focused laser beam operating in continuous-wave mode for noninvasive optical trapping and manipulation of single yeast cell. We verified that such operational mode of the laser does not cause any destructive effect on yeast cell wall. By changing the operation of the laser to f...

We report on optical levitation and manipulation of microscopic particles that are stuck on a glass surface with pulsed optical tweezers. An infrared pulse laser at 1.06 microm was used to generate a large gradient force (up to 10(-9) N) within a short duration (approximately 45 micros) that overcomes the adhesive interaction between the particles and the glass surface. Then a low-power continu...

We present a new tomographic phase microscopy (TPM) approach that allows capturing the three-dimensional refractive index structure of single cells in suspension without labeling, using 180° rotation of the cells. This is obtained by integrating an external off-axis interferometer for wide-field wave front acquisition with holographic optical tweezers (HOTs) for trapping and micro-rotation of t...

The Generalized Phase Contrast (GPC) method of optical 3D manipulation has previously been used for controlled spatial manipulation of live biological specimen in real-time. These biological experiments were carried out over a time-span of several hours while an operator intermittently optimized the optical system. Here we present GPC-based optical micromanipulation in a microfluidic system whe...

Near field generated by plasmonic structures has recently been proposed to trap small objects. We report the first integration of plasmonic trapping with microfluidics for lab-on-a-chip applications. A three-layer plasmo-microfluidic chip is used to demonstrate the trapping of polystyrene spheres and yeast cells. This technique enables cell immobilization without the complex optics required for...

Besides its importance as model organism in eukaryotic cell biology, yeast species have also developed into an attractive host for the expression, processing, and secretion of recombinant proteins. Here we investigated foreign protein secretion in four distantly related yeasts (Candida glabrata, Pichia pastoris, Saccharomyces cerevisiae, and Schizosaccharomyces pombe) by using green fluorescent...

An optical trapping system with a single-mode lensed fiber probe inserted at an angle is built; this system is simpler and more flexible than conventional optical tweezers. Two lasers, with 632.8- and 1550-nm wavelengths, are employed to trap and manipulate yeast cells and polystyrene microspheres. Nine yeast cells are manipulated to form a letter "T." Finally, the manipulation performed with v...

Background and Objective: Trichosporon asahii are basidiomycetous yeast-like anamorphic organisms and presently that are widely distributed in nature and found predominantly in tropical and temperate areas. Now it has been considered as an emerging nosoocomial pathogen with increasing morbidity and mortality. Urinary tract infections due to Trichosporon asahii, are frequently associated with in...