Quantitative and qualitative characteristics of greenery in suburban residential districts of Metro Manila

This case study was conducted to better understand the present situation of urban greenery in Marikina City, in the suburbs of metropolitan Manila, a typical large Asian city. A vegetation survey was conducted in residential districts of Marikina City, and the quantitative and qualitative characteristics of trees were analyzed. Lot size had some influence on the quantity of greenery in residential lots. In smaller lots, however, quantity did not increase in proportion to lot size. It appears, then, that the land-use controls for individual lots did not function effectively. Quantitative differences of greenery were related to qualitative differences, depending on the year or period of development of the residential area. In the newly developed residential lots, the greenery is comprised mostly of ornamental trees. Under the present circumstances, there is no assurance of sustaining the desired quantity of greenery in smaller residential lots. From these results, we proposed that regulations on lot size/coverage and promotion of tree planting involving local residents are needed to sustain urban greenery in residential districts

Involvement of the YneS/YgiH and PlsX proteins in phospholipid biosynthesis in both Bacillus subtilis and Escherichia coli

<p>Abstract</p> <p>Background</p> <p>Phospholipid biosynthesis commences with the acylation of glycerol-3-phosphate (G3P) to form 1-acyl-G3P. This step is catalyzed by the PlsB protein in <it>Escherichia coli</it>. The gene encoding this protein has not been identified, however, in the majority of bacterial genome sequences, including that of <it>Bacillus subtilis</it>. Recently, a new two-step pathway catalyzed by PlsX and PlsY proteins for the initiation of phospholipid formation in <it>Streptococcus pneumoniae </it>has been reported.</p> <p>Results</p> <p>In <it>B. subtilis</it>, 271 genes have been reported to be indispensable, when inactivated singly, for growth in LB medium. Among these, 11 genes encode proteins with unknown functions. As part of a genetic study to identify the functions of these genes, we show here that the <it>B. subtilis </it>ortholog of <it>S. pneumoniae </it>PlsY, YneS, is required for G3P acyltransferase activity, together with PlsX. The <it>B. subtilis </it>genome lacks <it>plsB</it>, and we show in vivo that the PlsX/Y pathway is indeed essential for the growth of bacteria lacking <it>plsB</it>. Interestingly, in addition to <it>plsB</it>, <it>E. coli </it>possesses <it>plsX </it>and the <it>plsY </it>ortholog, <it>ygiH</it>. We therefore explored the functional relationship between PlsB, PlsX and YgiH in <it>E. coli</it>, and found that <it>plsB </it>is essential for <it>E. coli </it>growth, indicating that PlsB plays an important role in 1-acyl-G3P synthesis in <it>E. coli</it>. We also found, however, that the simultaneous inactivation of <it>plsX </it>and <it>ygiH </it>was impossible, revealing important roles for PlsX and YgiH in <it>E. coli </it>growth.</p> <p>Conclusion</p> <p>Both <it>plsX </it>and <it>yneS </it>are essential for 1-acyl-G3P synthesis in <it>B. subtilis</it>, in agreement with recent reports on their biochemical functions. In <it>E. coli</it>, PlsB plays a principal role in 1-acyl-G3P synthesis and is also essential for bacterial growth. PlsX and YgiH also, however, play important roles in <it>E. coli </it>growth, possibly by regulating the intracellular concentration of acyl-ACP. These proteins are therefore important targets for development of new antibacterial agents.</p

Regulation of chromosomal replication initiation by oriC-proximal DnaA-box clusters in Bacillus subtilis

Bacterial chromosome replication is initiated by binding of DnaA to a DnaA-box cluster (DBC) within the replication origin (oriC). In Bacillus subtilis, six additional DBCs are found outside of oriC and some are known to be involved in transcriptional regulation of neighboring genes. A deletion mutant lacking the six DBCs (Δ6) initiated replication early. Further, inactivation of spo0J in Δ6 cells yielded a pleiotropic phenotype, accompanied by severe growth inhibition. However, a spontaneous suppressor in soj or a deletion of soj, which stimulates DnaA activity in the absence of Spo0J, counteracted these effects. Such abnormal phenotypic features were not observed in a mutant background in which replication initiation was driven by a plasmid-derived replication origin. Moreover, introduction of a single DBC at various ectopic positions within the Δ6 chromosome partly suppressed the early-initiation phenotype, but this was dependent on insertion location. We propose that DBCs negatively regulate replication initiation by interacting with DnaA molecules and play a major role, together with Spo0J/Soj, in regulating the activity of DnaA