Article Figures & Data
Figures
- Fig. 1.
Construction of strain SMU88. (A) Schematic representation of the A. vinelandii algU region and thealgU::Km mutation in plasmid pSMU88. Bar, 100 bp. (B) Southern blot hybridization of total genomic DNA digested with PstI endonuclease, with pSMU85 as a probe. Lanes: 1, ATCC 9046; 2, SMU88. Molecular sizes (in kilobases) are indicated on the right.
- Fig. 2.
Primer extension analysis of algDtranscription in strains SMU88 and ATCC 9046, with and without plasmid pSMU865. (A) DNA sequence of the 5′ end of algD. The arrows indicate the start sites of algD transcription, the p1 and p2 promoters are indicated (overbar), and the complementary sequences where oligonucleotides algD1 and algD2 (used for primer extension analysis) were generated are underlined. ThealgD ATG initiation codon is shown in boldface type. (B and C) Primer extension of the algD gene with oligonucleotidealgD1 in strains SMU88 (lane 1) and ATCC 9046 with (lane 2) and without (lane 3) plasmid pSMU865 (B) and with oligonucleotidealgD2 in strain SMU88 (C). The algD sequence ladders (GATC) were produced with the oligonucleotides used for primer extension.
- Fig. 3.
Electron micrographs were produced as described previously (19). Thin sections of A. vinelandiicysts formed by strains SMU88 (A), SMU88/pDMUM13 (B), ATCC 9046 (C), and ATCC 9046/pSMU865 (D) are shown. Abbreviations: EX, exine; IN, intine; CB, central body; PHB, poly-β-hydroxybutyrate. Bars, 0.4 μm.
Tables
- Table 1.
Alginate production and encystmenta
Strain Alginate (mg/mg of protein) Resistance to desiccation (%) ATCC 9046 2.5 ± 0.50 7.2 ± 1.5 ATCC 9046/pSMU865 0.46 ± 0.04 <0.0001 SMU88 0.003 ± 0.001 <0.0001 SMU88::pJMSAT1 2.74 ± 0.7 7.1 ± 2.5 SMU88/pDMUM13 0.170 ± 0.04 1.9 ± 0.5 UW136 0.004 ± 0.002 <0.0001 UW136::pJMSAT1 0.19 ± 0.02 8.8 ± 2.5 UW136/pDMUM13 0.16 ± 0.03 4.0 ± 1.0 ↵a Alginate production was determined in cells induced for encystment. Cells grown during 5 days on BS plates with 0.2% n-butanol as the sole carbon source were used to measure alginate production, as described previously (19). Encystment was determined as previously described (3). All values are means of three determinations (± standard deviations, where appropriate).
