Detection of blasts using flags and cell population data rules on Beckman Coulter DxH 900 hematology analyzer in patients with hematologic diseases.

OBJECTIVES: White blood cell (WBC)-related flags are essential for detecting abnormal cells including blasts in automated hematology analyzers (AHAs). Cell population data (CPD) may characterize each WBC population, and customized CPD rules can be also useful for detecting blasts. We evaluated the performance of WBC-related flags, customized CPD rules, and their combination for detecting blasts on the Beckman Coulter DxH 900 AHA (DxH 900, Beckman Coulter, Miami, Florida, USA). METHODS: In a total of 239 samples from patients with hematologic diseases, complete blood count on DxH 900 and manual slide review (MSR) were conducted. The sensitivity, specificity, and efficiency of the five WBC-related flags, nine customized CPD rules, and their combination were evaluated for detecting blasts, in comparison with MSR. RESULTS: Blasts were detected by MSR in 40 out of 239 (16.7 %) samples. The combination of flags and CPD rules showed the highest sensitivity compared with each of flags and CPD rules for detecting blasts (97.5 vs. 72.5 % vs. 92.5 %). Compared with any flag, the combination of flags and CPD rules significantly reduced false-negative samples from 11 to one for detecting blasts (27.5 vs. 2.5 %, p=0.002). CONCLUSIONS: This is the first study that evaluated the performance of both flags and CPD rules on DxH 900. The customized CPD rules as well as the combination of flags and CPD rules outperformed WBC-related flags for detecting blasts on DxH 900. The customized CPD rules can play a complementary role for improving the capability of blast detection on DxH 900.

Homo-succinic acid production by metabolically engineered Mannheimia succiniciproducens.

Succinic acid (SA) is a four carbon dicarboxylic acid of great industrial interest that can be produced by microbial fermentation. Here we report development of a high-yield homo-SA producing Mannheimia succiniciproducens strain by metabolic engineering. The PALFK strain (ldhA-, pta-, ackA-, fruA-) was developed based on optimization of carbon flux towards SA production while minimizing byproducts formation through the integrated application of in silico genome-scale metabolic flux analysis, omics analyses, and reconstruction of central carbon metabolism. Based on in silico simulation, utilization of sucrose would enhance the SA production and cell growth rates, while consumption of glycerol would reduce the byproduct formation rates. Thus, sucrose and glycerol were selected as dual carbon sources to improve the SA yield and productivity, while deregulation of catabolite-repression was also performed in engineered M. succiniciproducens. Fed-batch fermentations of PALFK with low- and medium-density (OD600 of 0.4 and 9.0, respectively) inocula produced 69.2 and 78.4g/L of homo-SA with yields of 1.56 and 1.64mol/mol glucose equivalent and overall volumetric SA productivities of 2.50 and 6.02g/L/h, respectively, using sucrose and glycerol as dual carbon sources. The SA productivity could be further increased to 38.6g/L/h by employing a membrane cell recycle bioreactor system. The systems metabolic engineering strategies employed here for achieving homo-SA production with the highest overall performance indices reported to date will be generally applicable for developing superior industrial microorganisms and competitive processes for the bio-based production of other chemicals as well.

Microbial production of building block chemicals and polymers.

Owing to our increasing concerns on the environment, climate change, and limited natural resources, there has recently been considerable effort exerted to produce chemicals and materials from renewable biomass. Polymers we use everyday can also be produced either by direct fermentation or by polymerization of monomers that are produced by fermentation. Recent advances in metabolic engineering combined with systems biology and synthetic biology are allowing us to more systematically develop superior strains and bioprocesses for the efficient production of polymers and monomers. Here, we review recent trends in microbial production of building block chemicals that can be subsequently used for the synthesis of polymers. Also, recent successful cases of direct one-step production of polymers are reviewed. General strategies for the production of natural and unnatural platform chemicals are described together with representative examples.