TABLE 2.

Diversity and predicted richness of nirK and nirS gene fragments from five subsurface samples along a nitrate and salinity gradient at Huntington Beach, California, as estimated by the Shannon diversity index and Chao1 and ACE richness estimators computed using DOTUR

Station and geneNo. of clones sequencedNo. of OTUsa (2%/5%)Chao1 valueACE valueShannon indexNo. of singletonsCoverage
nirK
    A3717/1317 (14, 35)20 (15, 45)2.2560.84
    B4722/1729 (20, 70)34 (22, 73)2.4390.81
    C4221/1932 (22, 70)54 (30, 134)2.50120.71
    D3422/1933 (23, 94)31 (22, 61)2.80110.68
    E3315/1331 (17, 94)36 (19, 109)2.1290.73
    All sites193
nirS
    A4629/2863 (40, 133)117 (69, 268)3.02210.54
    B4231/2975 (44, 168)90 (51, 200)3.26220.48
    C2723/2198 (43, 287)106 (44, 333)2.92180.33
    D4434/32113 (59, 273)125 (65, 292)3.31260.41
    E3624/2290 (41, 262)73 (38, 189)2.85170.53
    All sites195
  • a Numbers of OTUs are shown for both 2% and 5% differences in nucleic acid sequence alignments; richness estimators are shown for the 5% OTU cutoff. Numbers in parentheses are lower and upper 95% confidence intervals for the Chao1 and ACE estimators. Good's coverage estimates were also based on a 5% cutoff.