Since the early days of assisted reproductive technology (ART), the importance of sperm processing, employed to separate the motile, morphologically normal sperm from the semen, has been shown to be beneficial. The aim of the semen processing technique has been to remove seminal plasma and facilitate capacitation. Additionally, the presence of leukocytes, bacteria, and dead spermatozoa has been shown to be detrimental as it may cause oxidative stress that has an adverse effect on oocyte fertilization and embryo development. Hence, removal of leukocytes, bacteria, and dead spermatozoa is an important step of sperm processing for assisted reproduction. Currently, several sperm processing techniques have been evolved and optimized in the field of assisted reproduction. The requirements for in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and testicular sperm extraction (TESE) are different than those of intrauterine insemination (IUI). The yield of as many motile, morphologically normal sperm as possible is a prerequisite for the success of IVF insemination procedure. In ICSI, where injection of a single spermatozoon into the oocyte is performed by the embryologist, sperm selection techniques play a crucial role in the ICSI procedure. Finally, sperm retrieval in TESE samples with very low number of sperm may be challenging and requires extra care during sample processing. Additionally, sperm cryopreservation is necessary in TESE cases in order to avoid multiple biopsies.
Humans ; Sperm Injections, Intracytoplasmic/methods* ; Male ; Fertilization in Vitro/methods* ; Sperm Retrieval ; Andrology/methods* ; Cryopreservation ; Female ; Spermatozoa

Aims: Bacillus cereus is a Gram-positive, rod-shaped and spore-forming bacterium. It is a ubiquitous bacterium which is widely distributed in several environments such as soil and plants and is commonly isolated from food and its processing environment. This study was aimed to determine the genetic diversity and antibiotic resistance of B. cereus isolated from sago processing in Sarawak. Methodology and results: Out of 120 samples, 42 B. cereus isolates were detected with the presence of hly gene of B. cereus by using specific polymerase chain reaction (PCR). Twenty B. cereus isolates were randomly selected and further characterized by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with NotI to examine the genetic diversity. The result of the PFGE analysis confirmed that the B. cereus strains in sago processing were genetically diverse. Based on the dendrogram generated, B. cereus strains were grouped into two major clusters and these clusters were grouped together based on sources of isolation. The investigation on the antibiotic resistance of B. cereus strains revealed that the B. cereus strains were uniformly highly resistant to penicillin and ampicillin and highly susceptible to imipenem and norfloxacin. Conclusion, significance and impact of study The results of this study suggest that the B. cereus isolated from sago processing derived from a mixture of sensitive and resistant strains with diverse genetic contents.

Aims: Pigments have a large and growing market in the world. Drawbacks in their production such as raw materials availability and low productivity prompt the search for fermentation routes for industrial production. A carotenoid-producing yeast identified as Rhodotorula mucilaginosa was isolated in our laboratory. The aim of this study was to investigate the growth and carotenoid production capacity of the yeast. Methodology and results: A cost-effective substrate of sago starch hydrolysate (SSH) derived from sago fiber waste was used for the fermentation. The fermentation was carried out for 96 h at 27 °C in batch mode. The biomass produced during 5 days of fermentation was 9.6 g/L, which contained a carotenoid concentration of 8.1 mg/L and a specific yield of 845.9 g/g. Conclusion, significance and impact of study The results demonstrated the capacity of R. mucilaginosa yeast to produce carotenoids and its potential for larger-scale production.