Aims:This study was carried out to optimize the fermentation conditions using statistical approach for polyhydroxyalkanoate(PHA) production by a local isolate, Burkholderia cepaciaBPT1213, in the shake flask system.Methodology and results:Throughout this study, B. cepaciaBPT1213 was grown in minimal salt medium (MSM) supplemented with 2% of waste glycerol (86.70% purity).The strain can produce up to 1.33 g/L cell dry weight (CDW) with 22.21% of PHA content, thus giving a total PHA concentration 0.30 g/L before optimization. A factorial design experiment that was carried out showed all parameters KH2PO4, Na2HPO4·2H2O, carbon-to-nitrogen ratio (C/N), initial pH of medium, and temperature significantly affected the growth (cell dry weight, CDW) and PHA content. Response surface methodology (RSM) using central composite design (CCD) was then applied to optimize these parameters. The optimum conditions suggested were at 2.5 g/L KH2PO4, 4.5 g/L Na2HPO4·2H2O, 30 (g/g) C/N ratio, initial medium pH of 8.5 and 37 °C cultivation temperature, with a predicted CDW of 3.43 g/L and PHA content of 45.71% contributing to 1.57 g/L total PHA concentration. The verification experiment resulted in 3.60 g/L of CDW with 48.08% of PHA content contributing to 1.73 g/L total PHA concentration.Conclusion, significance and impact of study:The statistical approach using factorial design and RSM have succeeded in increasing the production of PHA by B. cepaciaBPT1213 using waste glycerol as the sole carbon source which is a promising renewable and cheaper feedsto

INTRODUCTIONDirect oral anticoagulants (DOACs) are establishing themselves as principle choices for the treatment of a variety of thrombotic disorders. DOACs are also known to affect common coagulation tests which are routinely performed for patients in clinical practice. An understanding of their varied effects is crucial for the appropriate ordering of coagulation tests and their interpretation.

MATERIALS AND METHODSLaboratories in public and private healthcare institutions and commercial sectors were surveyed on coagulation tests offered and their methods. A Medline and bibliography search, including a search on search engines, was performed for publications reporting the effects of dabigatran, apixaban and rivaroxaban on these coagulation tests. These papers were reviewed and summarised for consensus recommendations.

RESULTSProthrombin time (PT) and activated partial thromboplastin time (aPTT) are variably affected by the DOACs and dependent of the coagulation assays used. Clinicians must know which laboratory has performed these tests to logically interpret test results. A normal PT or aPTT does not exclude the presence of residual DOACs effect. The thrombin time is sensitive to dabigatran but not apixaban or rivaroxaban. Specialised coagulation tests such as thrombophilia tests are also variably affected by the DOACs. All laboratories in Singapore however, employ similar test methods permitting a common set of recommendations for specialised coagulation testing.

CONCLUSIONKnowledge of the effects of DOACs on coagulation testing is essential to determine the appropriateness of performing such tests and interpreting them coherently. Practical recommendations which are tests and location-specific are set out in this paper.

Antithrombins ; therapeutic use ; Blood Coagulation Tests ; Dabigatran ; therapeutic use ; Factor Xa Inhibitors ; therapeutic use ; Humans ; Partial Thromboplastin Time ; Practice Guidelines as Topic ; Prothrombin Time ; Pyrazoles ; therapeutic use ; Pyridones ; therapeutic use ; Rivaroxaban ; therapeutic use ; Singapore

Aims: Piper nigrum L. (black pepper) is an economically important commodity plant in Malaysia, which generated RM 200.95 million from pepper export in the year of 2018. However, the increase in pepper production is restricted by diseases. Fusarium wilt is one of the major diseases of P. nigrum L. The objectives for this study were to isolate Fusarium spp. associated with Fusarium wilt of P. nigrum L. from selected pepper farms in the northwestern region of Sarawak and to characterize the Fusarium spp. isolated morphologically and molecularly. Methodology and results: Fusarium spp. were isolated from diseased root samples. The pathogen was grown on potato dextrose agar (PDA) under dark condition at circa (ca.) 25 °C for morphological characterisation. Molecular characterisation was done by using internal transcribed spacer (ITS). Phylogenetic tree was constructed to study the genetic relationship of the isolates. Fusarium solani, F. oxysporum, F. proliferatum were the three Fusarium species identified. There were variations in morphological characters observed between and among the species, including the colony form, margin, elevation, surface appearance and pigmentation. No distinctive morphological characteristic was specific to a location. In addition, growth rate, macroconidia sporulation rate, and microconidia sporulation rate of the isolates were not correlated. In molecular phylogeny, the three Fusarium species were separated into three distinct clades representing the three identified species. The genetic relatedness between isolates within each species was depicted in the tree. Conclusion, significance and impact of study Variations were observed among isolates in this study based on morphological and molecular characterization. This study would contribute information on the variations of Fusarium spp. associated with Fusarium wilt of P. nigrum L. from the northwestern region of Sarawak.
Fusarium ; Fusariosis ; Piper nigrum