Table 2 Top 20 most frequently used keywords on keratinase researches over the survey period
From: Microbial keratinase and the bio-economy: a three-decade meta-analysis of research exploit
Rank | Author keywords (DE) | Freq. (% of 330) | Rank | Keywords-plus (ID) | Freq. (% of 330) |
|---|---|---|---|---|---|
1 | Keratinase | 188 (56.97) | 1 | Purification | 147 (44.55) |
2 | Keratin | 26 (7.88) | 2 | Degradation | 87 (26.36) |
3 | Protease | 22 (6.67) | 3 | Enzymes | 67 (20.30) |
3 | Purification | 21 (6.36) | 4 | Strain | 64 (19.39) |
4 | Feather degradation | 20 (6.06) | 5 | Protease | 53 (16.06) |
5 | Feather | 18 (5.46) | 6 | Alkaline protease | 42 (12.73) |
6 | Bacillus | 15 (4.55) | 7 | Bacterium | 40 (12.12) |
6 | Bacillus licheniformis | 15 (4.55) | 8 | Optimization | 39 (11.82) |
6 | Response surface methodology | 15 (4.55) | 9 | Extracellular keratinase | 35 (10.61) |
7 | Dehairing | 13 (3.94) | 10 | Proteinase | 35 (10.61) |
8 | Characterisation | 12 (3.64) | 11 | Feather | 34 (10.30) |
9 | Biodegradation | 11 (3.33) | 11 | Keratinase | 32 (9.69) |
9 | Keratinases | 11 (3.33) | 12 | Keratinolytic serine proteinase | 31 (9.39) |
9 | Optimization | 11 (3.33) | 13 | Expression | 30 (9.09) |
10 | Bacillus subtilis | 10 (3.03) | 13 | Enzyme | 26 (7.88) |
11 | Pseudomonas aeruginosa | 9 (2.73) | 14 | Subtilis | 26 (7.88) |
11 | Solid state fermentation | 9 (2.73) | 15 | Protein | 21 (6.36) |
12 | Bacillus pumilus | 8 (2.42) | 16 | Bacillus licheniformis | 20 (6.06) |
13 | Bacillus cereus | 7 (2.12) | 16 | Proteins | 20 (6.06) |
13 | Keratinolytic proteasea | 7 (2.12) | 16 | Keratinolytic activityb | 19 (5.76) |