Open Access

PCR-based Screening Approach: A Rapid Method to Detect the Biosynthetic Potential of Antimicrobials in Actinobacterial Strains


Cite

Fig. 1.

Neighbor-joining tree based on 16S rRNA gene sequences of closely related type strains. Evolutionary distance was calculated using Kimura 2-parameters with 1000 bootstrap value.
Neighbor-joining tree based on 16S rRNA gene sequences of closely related type strains. Evolutionary distance was calculated using Kimura 2-parameters with 1000 bootstrap value.

Fig. 2.

Antifungal activity of the selected polyene producing Streptomyces sp. against different fungal strains tested (Fusarium oxysporum (FO), Rhizoctonia solani (RS), and Aspergillus sp. (FN2). (A), (B), (C) Anti fungal activity of NR-1, NR-10, and NR-15 by the agar plug method against Fusarium oxysporum (FO), Rhizoctonia solani (RS). (D), (E), (F) Activity of NR-1, NR-14, and NR-15 by the agar plug method against Aspergillus sp. (FN2). (G), (H), (I) Activity of NR-1, NR-14, NR-10, H26, and CHX (cycloheximide) by the well diffusion method against Aspergillus sp.
Antifungal activity of the selected polyene producing Streptomyces sp. against different fungal strains tested (Fusarium oxysporum (FO), Rhizoctonia solani (RS), and Aspergillus sp. (FN2). (A), (B), (C) Anti fungal activity of NR-1, NR-10, and NR-15 by the agar plug method against Fusarium oxysporum (FO), Rhizoctonia solani (RS). (D), (E), (F) Activity of NR-1, NR-14, and NR-15 by the agar plug method against Aspergillus sp. (FN2). (G), (H), (I) Activity of NR-1, NR-14, NR-10, H26, and CHX (cycloheximide) by the well diffusion method against Aspergillus sp.

Fig. 3.

Chemical profile of the selected Actinomycetes strains. (A) TLC plate at 366 nm. (B) TLC plate after spraying with Ehrlich’s reagent. (C) TLC plate after spraying with anisaldehyde reagent.
Chemical profile of the selected Actinomycetes strains. (A) TLC plate at 366 nm. (B) TLC plate after spraying with Ehrlich’s reagent. (C) TLC plate after spraying with anisaldehyde reagent.

Fig 4.

HPLC analysis of crude extracts of the polyene producing Streptomyces sp. (A) HPLC chromatogram of strain NR-1, (B) HPLC chromatogram of strain NR-10, (C) HPLC chromatogram of strain NR-14, (D) HPLC chromatogram of strain NR-15.
HPLC analysis of crude extracts of the polyene producing Streptomyces sp. (A) HPLC chromatogram of strain NR-1, (B) HPLC chromatogram of strain NR-10, (C) HPLC chromatogram of strain NR-14, (D) HPLC chromatogram of strain NR-15.

Fig. 5.

The relative abundance of the nrps, pks-1, cyps, oxy b genes in the selected Streptomyces strains.
The relative abundance of the nrps, pks-1, cyps, oxy b genes in the selected Streptomyces strains.

Antifungal activity of the selected polyene producing Streptomyces sp. against different fungal strains (Fusarium oxysporum, Rhizoctonia solani, and Aspergillus sp.).

The fungus strain tested Zone of inhibition in mm
NR-1 NR-10 NR-14 NR-15 MM7 CHX
Fusarium oxysporum 17.0 ± 0.11 17.8 ± 0.18 14.7 ± 0.22 16.0 ± 0.25 5.1 ± 0.121   9.9 ± 0.26
Rhizoctonia solani 18.0 ± 0.32 12.2 ± 0.41 13.8 ± 0.45 16.6 ± 0.45 0.2 ± 0.11   10.9 ± 0.53
Aspergillus sp. 22.1 ± 0.40 19.0 ± 0.12 18.8 ± 0.27 18.3 ± 0.38 1.7 ± 0.42   14.0 ± 0.18

PCR primers for the nrps, pks-1, cyps, and oxy b genes.

Genes Primers Sequence (5’-3’) Length Tm Product size References
cyps CYP-F TGGATCGGCGACGACCGSVYCGT 23 bp 63.8 350 bp Ayuso-Sacido and Genilloud 2005
CYP-R CCGWASAGSAYSCCGTCGTACTT 23 bp 56.6
oxy b GLY-F CTGGTCGGCAACCTGATGGAC 21 bp 61.7 560 bp Ayuso-Sacido and Genilloud 2005
GLY-R CAGGTACCGGATCAGCTCGTC 21 bp 61.7
pks1 K1F TSAAGTCSAACATCGGBCA 19 bp 48.4 1200–1500 bp Ayuso-Sacido and Genilloud 2005
M6R CGCAGGTTSCSGTACCAGTA 20 bp 55.4
nrps A3F GCSTACSYSATSTACACSTCSGG 23 bp 53.1 700 bp Wood et al 2007
A7R SASGTCVCCSGTSCGGTAS 19 bp 50.6

Streptomyces sp. GenBank accession numbers of 16S rRNA genes.

S. No. Given Code of Strain GenBank Accession No. Identified as
NR-1 MK243371 Streptomyces sp.
NR-10 MK243372 Streptomyces sp.
NR14 MK243373 Streptomyces sp.
NR15 MK243374 Streptomyces sp.
NR11 MN912434 Streptomyces sp.
C2 MN912435 Streptomyces pseudovenezuelae
D6-3 MN912436 Streptomyces flavogriseus
H34A MN912437 Streptomyces sp.
H34B MN912438 Streptomyces sp.
NR28 MN912439 Streptomyces flavoviridis
NR1 MN912440 Streptomyces sp.
NR5 MN912441 Streptomyces werraensis
10M MN912442 Streptomyces sp.
C3 MN912443 Streptomyces fenghuangensis
H32B MN912444 Streptomyces sp.
B5K MN912445 Streptomyces fimbriatus
H31A MN912446 Nocardioides sp.
M19 MN912447 Streptomyces albogriseolus
MM5 MN912448 Streptomyces Streptomyces griseus
NR3 MN912449 Streptomyces sp.
M63 MN912450 Streptomyces misionensis
M32 MN912451 Streptomyces sp.
M12 MN912452 Streptomyces steffisburgensis.
MM7 MN912453 Streptomyces fimbriatus.
M13 MN912454 Streptomyces niveoruber
D3-1 MN912455 Streptomyces bambusae
M29 MN912456 Streptomyces sp.
M28 MN912457 Streptomyces coerulescens
NR24 MN912458 Streptomyces silaceus
NR22 MN912459 Streptomyces sp.
H26 MN912460 Streptomyces steffisburgensis
M43 MN912461 Streptomyces rubrolavendulae
NR12 MN912462 Streptomyces neopeptinius
NR6 MN912463 Streptomyces coeruleoprunus
D3-3 MN912464 Streptomyces sp.
D3-2 MN912465 Streptomyces sp.
M93 KM062032 Streptomyces laurentii
M71 KM062033 Streptomyces vitaminophilus
M54 KM062034 Streptomyces hypolithicus
M51 KM062035 Streptomyces chartreusis

Streptomyces sp. GenBank accession numbers of the genes sequences.

S. No. Isolates Nucleotide length GenBank Accession No. % age homology Genes encoding for
1. NR-1   350 bp   98 CYP MF279145
2. NR-10   350 bp 100 CYP MF279146
3. NR14   350 bp   98 CYP MK272790
4. NR15   350 bp   98 CYP MK272791
5. NR-16   700 bp 100 NRPS MF279147
6. M13   700 bp   99 NRPS MF279148
7. NR-12   700 bp   98 NRPS MF279150
8. NR-6   1500 bp   98 PKS-1 MF279149

The translated DNA sequence of NR-1 based on six reading frames and their percentage similarity with cytochrome P450 hydroxylase (CYP) protein.

Sequence translation (EMBOSS Transq) % similarity with cytochrome P450 hydroxylase protein
EMBOSS_001_1 98
EMBOSS_001_2 50
EMBOSS_001_3 No significant similarity found
EMBOSS_001_4 45
EMBOSS_001_5 No significant similarity found
EMBOSS_001_6 No significant similarity found
eISSN:
2544-4646
Language:
English
Publication timeframe:
4 times per year
Journal Subjects:
Life Sciences, Microbiology and Virology