The error is following -
(base) abhisek062@abhisek-PC:~/Downloads/mothur-1.48.0$ ./Makefile
./Makefile: line 23: INSTALL_DIR: command not found
./Makefile: line 25: OPTIMIZE: command not found
./Makefile: line 26: USEREADLINE: command not found
./Makefile: line 27: USEBOOST: command not found
./Makefile: line 28: USEHDF5: command not found
./Makefile: line 29: USEGSL: command not found
./Makefile: line 30: LOGFILE_NAME: command not found
./Makefile: line 32: BOOST_LIBRARY_DIR: command not found
./Makefile: line 33: BOOST_INCLUDE_DIR: command not found
./Makefile: line 34: HDF5_LIBRARY_DIR: command not found
./Makefile: line 35: HDF5_INCLUDE_DIR: command not found
./Makefile: line 36: GSL_LIBRARY_DIR: command not found
./Makefile: line 37: GSL_INCLUDE_DIR: command not found
./Makefile: line 40: VERSION: command not found
./Makefile: line 41: RELEASE_DATE: command not found
./Makefile: line 45: syntax error near unexpected token $(strip $(LOGFILE_NAME)),yes' ./Makefile: line 45:
ifeq ($(strip $(LOGFILE_NAME)),yes)’