# Marine Bacteria Associated with Colonization and Alteration of Plastic Polymers
## 3 Results and Discussion
### In Vitro Colonization and Structural Changes of Polymers through FTIR
**(A)** Spectra from polymers without inoculum (control) and with each one being bacteria inoculated; **(B)** Detail of spectra in vibration band between 3100 and 2500 cm\({}^{-1}\); **(C)** Detail of spectra in vibration band between 1600 and 1000 cm\({}^{-1}\); **(D)** Detail of spectra in vibration band between 1100 and 750 cm\({}^{-1}\). Red line corresponds to PP whose spheres inoculated with _Acaligenes faecalis_, blue line with _Bacillus cereus_, green line with _Bacillus_ sp., light blue line with _Bacillus thuringiensis_, orange line with _Myroides gitamensis_, pink line with _Proteus penneri_ and black line corresponds to PP spheres without inoculum (control). Arrows are indicative of flattening peak (in **B**) and double peaks (in **C**). Figure 2: FTIR spectra of mechanically crushed spheres of polypropylene (PP). **(A)** spectra from polymers without inoculum (control) and with each one being bacteria inoculated; **(B)** Detail of spectra in vibration band between 3100 and 2500 cm\({}^{-1}\); **(C)** Detail of spectra in vibration band between 1600 and 1000 cm\({}^{-1}\); **(D)** Detail of spectra in vibration band between 1100 and 750 cm\({}^{-1}\). Red line corresponds to PP mechanically crushed spheres inoculated with _Acaligenes faecalis_, blue line with _Bacillus cereus_, green line with _Bacillus thuringiensis_, orange line with _Myroides gitamensis_, pink line with _Proteus penneri_ and black line corresponds to PP spheres without inoculum (control). Arrows are indicative of flattening peak (in **B**) and triple peaks (in **C**). Figure 4: FTIR spectra of mechanically crushed spheres of polystyrene (PS). (**A**) Spectra from polymers without inoculum (control) and with each one being bacteria inoculated; (**B**) Detail of spectra in vibration band between 3100 and 2500 cm\({}^{-1}\); (**C**) Detail of spectra in vibration band between 1600 and 1000 cm\({}^{-1}\); (**D**) Detail of spectra in vibration band between 1100 and 750 cm\({}^{-1}\). Red line corresponds to PS mechanically crushed spheres inoculated with _Alcaligenes faecalis_, blue line with _Bacillus cereus_, green line with _Bacillus_ sp., light blue line with _Bacillus thuringiensis_, orange line with _Myroides giamensis_, pink line with _Proteus penneri_ and black line corresponds to PP spheres without inoculum (control). Figure 3: FTIR spectra of whole spheres of polystyrene (PS). (**A**) Spectra from polymers without inoculum (control) and with each one being bacteria inoculated; (**B**) Detail of spectra in vibration band between 3100 and 2500 cm\({}^{-1}\); (**C**) Detail of spectra in vibration band between 1600 and 1000 cm\({}^{-1}\); (**D**) Detail of spectra in vibration band between 1100 and 750 cm\({}^{-1}\). Red line corresponds to PS whole spheres inoculated with _Alcaligenes faecalis_, blue line with _Bacillus cereus_, green line with _Bacillus_ sp., light blue line with _Bacillus thuringiensis_, orange line with _Myroides giamensis_, pink line with _Proteus penneri_ and black line corresponds to PP spheres without inoculum (control). Results seem to suggest that the type of polymer, alongside metabolic adaptation of bacteria (i.e., polysaccharide production; [47; 48]), may affect bacteria growth and their polymer attachment. In addition to chemical properties of plastic polymer spheres, differences between vibration bands of whole and mechanically crushed spheres might also be caused by grooves and pits inadvertently introduced during crushing [49]. In summary, type (PP vs. PS) and state (whole vs. mechanically crushed spheres) of plastic polymer would affect colonization and alteration of polymers by bacteria. By comparing all the spectra obtained from plastic spheres that were inoculated with different bacteria, it is concluded that bacteria successfully reduced the C-H stretches around 1460 cm\({}^{-1}\) and C-H vibrations at 3000 cm\({}^{-1}\). These results open a door to further study if co-occurrence of bacteria (bacteria consortia) can favor changes in PS spectra and improve polymer bioalteration.